668625867 has 32 divisors (see below), whose sum is σ = 1219151360. Its totient is φ = 352680480.

The previous prime is 668625863. The next prime is 668625931. The reversal of 668625867 is 768526866.

668625867 is a `hidden beast` number, since 6 + 6 + 8 + 625 + 8 + 6 + 7 = 666.

It is not a de Polignac number, because 668625867 - 2² = 668625863 is a prime.

It is not an unprimeable number, because it can be changed into a prime (668625863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 133609 + ... + 138522.

It is an arithmetic number, because the mean of its divisors is an integer number (38098480).

Almost surely, 2^668625867 is an apocalyptic number.

668625867 is a deficient number, since it is larger than the sum of its proper divisors (550525493).

668625867 is a wasteful number, since it uses less digits than its factorization.

668625867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272160 (or 272154 counting only the distinct ones).

The product of its digits is 5806080, while the sum is 54.

The square root of 668625867 is about 25857.8008925740. The cubic root of 668625867 is about 874.4353873689.

Subtracting 668625867 from its reverse (768526866), we obtain a palindrome (99900999).

The spelling of 668625867 in words is "six hundred sixty-eight million, six hundred twenty-five thousand, eight hundred sixty-seven".