856440520 has 32 divisors (see below), whose sum is σ = 2075222520. Its totient is φ = 316224000.

The previous prime is 856440493. The next prime is 856440547. The reversal of 856440520 is 25044658.

It is an interprime number because it is at equal distance from previous prime (856440493) and next prime (856440547).

It can be written as a sum of positive squares in 4 ways, for example, as 493995076 + 362445444 = 22226^2 + 19038^2 .

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 822981 + ... + 824020.

Almost surely, 2^856440520 is an apocalyptic number.

It is an amenable number.

856440520 is an abundant number, since it is smaller than the sum of its proper divisors (1218782000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

856440520 is a wasteful number, since it uses less digits than its factorization.

856440520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1647025 (or 1647021 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 34.

The square root of 856440520 is about 29265.0050401499. The cubic root of 856440520 is about 949.6547295615.

The spelling of 856440520 in words is "eight hundred fifty-six million, four hundred forty thousand, five hundred twenty".