521656313 has 4 divisors (see below), whose sum is σ = 538483968. Its totient is φ = 504828660.

The previous prime is 521656283. The next prime is 521656319. The reversal of 521656313 is 313656125.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 521656313 - 2⁶ = 521656249 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 521656313.

It is not an unprimeable number, because it can be changed into a prime (521656319) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8413781 + ... + 8413842.

It is an arithmetic number, because the mean of its divisors is an integer number (134620992).

Almost surely, 2^521656313 is an apocalyptic number.

It is an amenable number.

521656313 is a deficient number, since it is larger than the sum of its proper divisors (16827655).

521656313 is a wasteful number, since it uses less digits than its factorization.

521656313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16827654.

The product of its digits is 16200, while the sum is 32.

The square root of 521656313 is about 22839.7966934909. The cubic root of 521656313 is about 804.9980391655.

The spelling of 521656313 in words is "five hundred twenty-one million, six hundred fifty-six thousand, three hundred thirteen".