21331319951 has 2 divisors, whose sum is σ = 21331319952. Its totient is φ = 21331319950.

The previous prime is 21331319921. The next prime is 21331320013. The reversal of 21331319951 is 15991313312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21331319951 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21331319921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10665659975 + 10665659976.

It is an arithmetic number, because the mean of its divisors is an integer number (10665659976).

Almost surely, 2^21331319951 is an apocalyptic number.

21331319951 is a deficient number, since it is larger than the sum of its proper divisors (1).

21331319951 is an equidigital number, since it uses as much as digits as its factorization.

21331319951 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21870, while the sum is 38.

The spelling of 21331319951 in words is "twenty-one billion, three hundred thirty-one million, three hundred nineteen thousand, nine hundred fifty-one".