315516645442021 has 2 divisors, whose sum is σ = 315516645442022. Its totient is φ = 315516645442020.

The previous prime is 315516645441931. The next prime is 315516645442039. The reversal of 315516645442021 is 120244546615513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 210330801761796 + 105185843680225 = 14502786^2 + 10256015^2 .

It is a cyclic number.

It is not a de Polignac number, because 315516645442021 - 2¹⁷ = 315516645310949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (315516645442421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157758322721010 + 157758322721011.

It is an arithmetic number, because the mean of its divisors is an integer number (157758322721011).

Almost surely, 2^{315516645442021} is an apocalyptic number.

It is an amenable number.

315516645442021 is a deficient number, since it is larger than the sum of its proper divisors (1).

315516645442021 is an equidigital number, since it uses as much as digits as its factorization.

315516645442021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456000, while the sum is 49.

The spelling of 315516645442021 in words is "three hundred fifteen trillion, five hundred sixteen billion, six hundred forty-five million, four hundred forty-two thousand, twenty-one".