666889628 has 24 divisors (see below), whose sum is σ = 1200517584. Its totient is φ = 323913600.

The previous prime is 666889603. The next prime is 666889631. The reversal of 666889628 is 826988666.

It is a congruent number.

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, 99008 + ... + 105528.

It is an arithmetic number, because the mean of its divisors is an integer number (50021566).

Almost surely, 2^666889628 is an apocalyptic number.

It is an amenable number.

666889628 is a deficient number, since it is larger than the sum of its proper divisors (533627956).

666889628 is a wasteful number, since it uses less digits than its factorization.

666889628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7253 (or 7251 counting only the distinct ones).

The product of its digits is 11943936, while the sum is 59.

The square root of 666889628 is about 25824.2062414317. The cubic root of 666889628 is about 873.6778412141.

The spelling of 666889628 in words is "six hundred sixty-six million, eight hundred eighty-nine thousand, six hundred twenty-eight".