231313118021 has 2 divisors, whose sum is σ = 231313118022. Its totient is φ = 231313118020.

The previous prime is 231313117993. The next prime is 231313118033. The reversal of 231313118021 is 120811313132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 228039676225 + 3273441796 = 477535^2 + 57214^2 .

It is a cyclic number.

It is not a de Polignac number, because 231313118021 - 2²² = 231308923717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231313118081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115656559010 + 115656559011.

It is an arithmetic number, because the mean of its divisors is an integer number (115656559011).

Almost surely, 2^231313118021 is an apocalyptic number.

It is an amenable number.

231313118021 is a deficient number, since it is larger than the sum of its proper divisors (1).

231313118021 is an equidigital number, since it uses as much as digits as its factorization.

231313118021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 26.

The spelling of 231313118021 in words is "two hundred thirty-one billion, three hundred thirteen million, one hundred eighteen thousand, twenty-one".