856657865538 has 16 divisors (see below), whose sum is σ = 1903684145760. Its totient is φ = 285552621828.

The previous prime is 856657865527. The next prime is 856657865551. The reversal of 856657865538 is 835568756658.

856657865538 is a `hidden beast` number, since 8 + 5 + 6 + 6 + 5 + 7 + 86 + 5 + 538 = 666.

856657865538 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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, 7932017220 + ... + 7932017327.

It is an arithmetic number, because the mean of its divisors is an integer number (118980259110).

Almost surely, 2^856657865538 is an apocalyptic number.

856657865538 is an abundant number, since it is smaller than the sum of its proper divisors (1047026280222).

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

856657865538 is a wasteful number, since it uses less digits than its factorization.

856657865538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15864034558 (or 15864034552 counting only the distinct ones).

The product of its digits is 1451520000, while the sum is 72.

The spelling of 856657865538 in words is "eight hundred fifty-six billion, six hundred fifty-seven million, eight hundred sixty-five thousand, five hundred thirty-eight".