Nineteen thousand nine hundred ninety one
19991 is an odd number.
19991 is a prime number, which means it is only divisible by 1 and itself.
19991 is a palindrome.
19991 is a Sophie Germain prime, which means that 2 x 19991 + 1 = 39983 is also a prime number.
In binary, 19991 is represented as 100111000010111.
In hex, 19991 is represented as 4e17.
Prime factorization of 19991: 19991.