856507665 has 32 divisors (see below), whose sum is σ = 1477284480. Its totient is φ = 421249536.

The previous prime is 856507637. The next prime is 856507667. The reversal of 856507665 is 566705658.

It is not a de Polignac number, because 856507665 - 2⁵ = 856507633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (856507667) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 314349 + ... + 317061.

It is an arithmetic number, because the mean of its divisors is an integer number (46165140).

Almost surely, 2^856507665 is an apocalyptic number.

It is an amenable number.

856507665 is a deficient number, since it is larger than the sum of its proper divisors (620776815).

856507665 is a wasteful number, since it uses less digits than its factorization.

856507665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4353.

The product of its (nonzero) digits is 1512000, while the sum is 48.

The square root of 856507665 is about 29266.1522069438. The cubic root of 856507665 is about 949.6795465800.

The spelling of 856507665 in words is "eight hundred fifty-six million, five hundred seven thousand, six hundred sixty-five".