668525866 has 24 divisors (see below), whose sum is σ = 1064042784. Its totient is φ = 314924280.

The previous prime is 668525863. The next prime is 668525909.

It is a happy number.

668525866 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×668525866² = 893853667022099912, which contains 22 as substring.

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 11 ways as a sum of consecutive naturals, for example, 66171 + ... + 75601.

It is an arithmetic number, because the mean of its divisors is an integer number (44335116).

Almost surely, 2^668525866 is an apocalyptic number.

668525866 is a deficient number, since it is larger than the sum of its proper divisors (395516918).

668525866 is a wasteful number, since it uses less digits than its factorization.

668525866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9546 (or 9523 counting only the distinct ones).

The product of its digits is 4147200, while the sum is 52.

The square root of 668525866 is about 25855.8671484830. The cubic root of 668525866 is about 874.3917911032.

The spelling of 668525866 in words is "six hundred sixty-eight million, five hundred twenty-five thousand, eight hundred sixty-six".