- Question: I am the first perfect number, what am I?
Answer: Six - Question: What number can be written as the sum of three consecutive primes?
Answer: Ten - Question: I am a prime number that’s also a palindrome, what am I?
Answer: Eleven - Question: I am the only even prime number, what am I?
Answer: Two - Question: What’s the smallest number with exactly five divisors?
Answer: Sixteen - Question: I am the sum of the first four positive perfect squares, what am I?
Answer: Thirty - Question: What’s the only number that’s equal to the sum of its divisors excluding itself?
Answer: Twenty-eight - Question: I am the smallest Fibonacci number to contain all ten digits, what am I?
Answer: Eighty-nine - Question: What number is both the square of a prime and the cube of another prime?
Answer: Twenty-seven - Question: I am the only number with letters in alphabetical order, what am I?
Answer: Forty - Question: What’s the smallest composite number that’s also a perfect square?
Answer: Four - Question: I am the product of the first four prime numbers, what am I?
Answer: Two hundred and ten - Question: What number is both the sum and the product of its digits?
Answer: Twenty-four - Question: I am the only number that’s equal to the sum of the factorial of my digits, what am I?
Answer: One hundred and forty-four - Question: What number is represented by the Roman numeral “C” in base 10?
Answer: One hundred - Question: I am the smallest number that’s divisible by all numbers from 1 to 10, what am I?
Answer: Two hundred and forty - Question: What number is both a triangular number and a hexagonal number?
Answer: Twenty-one - Question: I am the sum of the first four positive cubes, what am I?
Answer: One hundred and one - Question: What’s the smallest number that’s both a Fibonacci number and a Lucas number?
Answer: Three - Question: I am the largest number with a single syllable, what am I?
Answer: Twelve
- Question: I am the smallest positive integer with no digits in common with its cube, what am I?
Answer: Seven - Question: What’s the only number whose English name has all its letters in alphabetical order?
Answer: Forty-eight - Question: I am the smallest number that’s both a square and a cube, what am I?
Answer: One - Question: What number is represented by the hexadecimal “A” in base 10?
Answer: Ten - Question: I am the smallest number that’s both a square and a palindrome, what am I?
Answer: One - Question: What’s the only number that’s both a square and a triangular number?
Answer: One - Question: I am the sum of the first four prime numbers, what am I?
Answer: Twenty-two - Question: What number is both a triangular number and a pentagonal number?
Answer: One - Question: I am the smallest number that’s the product of two different primes, what am I?
Answer: Six - Question: What’s the only number that’s equal to the sum of the squares of its digits?
Answer: Eighty-one - Question: I am the smallest number that’s both a palindrome and a product of two primes, what am I?
Answer: Twenty-two - Question: What number is represented by the Roman numeral “D” in base 10?
Answer: Five hundred - Question: I am the smallest number with exactly six divisors, what am I?
Answer: Twelve - Question: What’s the only number whose English name has its letters in reverse alphabetical order?
Answer: Ninety - Question: I am the smallest number with exactly eight divisors, what am I?
Answer: Twenty-four - Question: What number is both a square and the sum of two consecutive cubes?
Answer: Thirty-six - Question: I am the smallest number with exactly nine divisors, what am I?
Answer: Twenty-four - Question: What’s the only number that’s equal to the sum of the cubes of its digits?
Answer: One hundred and fifty-four - Question: I am the smallest number with exactly ten divisors, what am I?
Answer: Forty-eight - Question: What number is represented by the Roman numeral “M” in base 10?
Answer: One thousand
Another Number riddles
- Question: I am the smallest number that’s the sum of two positive cubes in more than one way, what am I?
Answer: Seventeen - Question: What number is represented by the Roman numeral “L” in base 10?
Answer: Fifty - Question: I am the smallest number that’s both a prime and a Fibonacci number, what am I?
Answer: Two - Question: What’s the only number that’s equal to the sum of its divisors excluding itself, squared?
Answer: Eighty-one - Question: I am the smallest number that’s the sum of two positive squares in more than one way, what am I?
Answer: Eight - Question: What number is both a square and a palindrome?
Answer: One - Question: I am the smallest number with exactly seven divisors, what am I?
Answer: Forty-two - Question: What’s the only number whose English name has all its letters in reverse alphabetical order?
Answer: Fifty - Question: I am the smallest number that’s the sum of two different primes in more than one way, what am I?
Answer: Four - Question: What number is represented by the hexadecimal “F” in base 10?
Answer: Fifteen - Question: I am the smallest number that’s both a square and a cube of another number, what am I?
Answer: One - Question: What’s the only number that’s equal to the sum of the factorials of its digits?
Answer: One hundred and forty-three - Question: I am the smallest number with exactly eleven divisors, what am I?
Answer: Sixty - Question: What number is both a triangular number and a square?
Answer: One - Question: I am the smallest number with exactly twelve divisors, what am I?
Answer: Sixty - Question: What’s the only number that’s equal to the sum of its divisors excluding itself, cubed?
Answer: One thousand and twenty-four - Question: I am the smallest number that’s the sum of two consecutive primes, what am I?
Answer: Five - Question: What number is represented by the Roman numeral “V” in base 10?
Answer: Five - Question: I am the smallest number with exactly thirteen divisors, what am I?
Answer: Seventy-eight - Question: What’s the only number that’s equal to the sum of the cubes of its digits, squared?
Answer: Three hundred and twenty-four
- Question: I am the smallest number with exactly fourteen divisors, what am I?
Answer: One hundred and twenty - Question: What number is both a square and the sum of two consecutive cubes?
Answer: Thirty-six - Question: I am the smallest number that’s the sum of three positive squares in more than one way, what am I?
Answer: Fifty-two - Question: What’s the only number whose English name has all its letters in alphabetical order except one?
Answer: Forty - Question: I am the smallest number with exactly fifteen divisors, what am I?
Answer: Five hundred and four - Question: What number is represented by the Roman numeral “CXL” in base 10?
Answer: One hundred and forty - Question: I am the smallest number with exactly sixteen divisors, what am I?
Answer: One hundred and twenty-eight - Question: What’s the only number that’s equal to the sum of its digits multiplied by the number of digits?
Answer: Eighteen - Question: I am the smallest number with exactly seventeen divisors, what am I?
Answer: Five hundred and forty - Question: What number is both a triangular number and a square?
Answer: One - Question: I am the smallest number with exactly eighteen divisors, what am I?
Answer: Two hundred and forty - Question: What’s the only number that’s equal to the sum of its digits raised to the power of the number of digits?
Answer: One hundred and twenty-one - Question: I am the smallest number with exactly nineteen divisors, what am I?
Answer: Six hundred and sixty - Question: What number is both a square and the sum of two consecutive triangular numbers?
Answer: Nine - Question: I am the smallest number with exactly twenty divisors, what am I?
Answer: Four hundred and ninety-six - Question: What’s the only number whose English name has its letters in alphabetical order except one?
Answer: Forty - Question: I am the smallest number with exactly twenty-one divisors, what am I?
Answer: Four hundred and eighty - Question: What number is represented by the Roman numeral “DXL” in base 10?
Answer: Five hundred and forty - Question: I am the smallest number with exactly twenty-two divisors, what am I?
Answer: Four hundred and forty - Question: What’s the only number that’s equal to the sum of the factorial of its digits?
Answer: One hundred and forty-three
Getting over with Number riddles
- I am the only even prime number. What am I?
- I am the square root of 144. What number am I?
- What number, when added to its square, equals 10?
- I am the sum of the first four prime numbers. What number am I?
- I am the only number that is both a perfect square and a perfect cube. What am I?
- Take half of me, and you get 25. What number am I?
- I am the smallest two-digit prime number. What number am I?
- What number, when multiplied by itself, equals 81?
- I am the number of sides on a pentagon. What am I?
- What number comes after twelve but before fourteen?
- I am the product of 6 and 7. What number am I?
- What number, when doubled, equals 24?
- I am one less than a perfect square and one more than a multiple of 10. What am I?
- What number is represented by the Roman numeral “XVIII”?
- I am the smallest three-digit prime number. What number am I?
- I am the only number that is both the sum and the product of the first four positive integers. What am I?
- What number is represented by the binary numeral “1010”?
- I am the sum of the first five positive even numbers. What number am I?
- I am the number of months in a leap year. What am I?
- What number, when divided by 3, leaves a remainder of 2?
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