315312521 has 2 divisors, whose sum is σ = 315312522. Its totient is φ = 315312520.

The previous prime is 315312511. The next prime is 315312523. The reversal of 315312521 is 125213513.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 203376121 + 111936400 = 14261^2 + 10580^2 .

It is a cyclic number.

It is not a de Polignac number, because 315312521 - 2¹⁸ = 315050377 is a prime.

It is a Sophie Germain prime.

Together with 315312523, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (315312523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157656260 + 157656261.

It is an arithmetic number, because the mean of its divisors is an integer number (157656261).

Almost surely, 2^315312521 is an apocalyptic number.

It is an amenable number.

315312521 is a deficient number, since it is larger than the sum of its proper divisors (1).

315312521 is an equidigital number, since it uses as much as digits as its factorization.

315312521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 900, while the sum is 23.

The square root of 315312521 is about 17757.0414483945. The cubic root of 315312521 is about 680.6341553869.

The spelling of 315312521 in words is "three hundred fifteen million, three hundred twelve thousand, five hundred twenty-one".