668525865 has 32 divisors (see below), whose sum is σ = 1247404800. Its totient is φ = 305609472.

The previous prime is 668525863. The next prime is 668525909. The reversal of 668525865 is 568525866.

It is not a de Polignac number, because 668525865 - 2¹ = 668525863 is a prime.

It is not an unprimeable number, because it can be changed into a prime (668525861) 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, 59824 + ... + 70113.

It is an arithmetic number, because the mean of its divisors is an integer number (38981400).

Almost surely, 2^668525865 is an apocalyptic number.

It is an amenable number.

668525865 is a deficient number, since it is larger than the sum of its proper divisors (578878935).

668525865 is a wasteful number, since it uses less digits than its factorization.

668525865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129966 (or 129952 counting only the distinct ones).

The product of its digits is 3456000, while the sum is 51.

The square root of 668525865 is about 25855.8671291450. The cubic root of 668525865 is about 874.3917906672.

Subtracting from 668525865 its reverse (568525866), we obtain a palindrome (99999999).

The spelling of 668525865 in words is "six hundred sixty-eight million, five hundred twenty-five thousand, eight hundred sixty-five".