656629980 has 24 divisors (see below), whose sum is σ = 1838564112. Its totient is φ = 175101312.

The previous prime is 656629973. The next prime is 656629991. The reversal of 656629980 is 89926656.

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, 5471857 + ... + 5471976.

It is an arithmetic number, because the mean of its divisors is an integer number (76606838).

Almost surely, 2^656629980 is an apocalyptic number.

656629980 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

656629980 is an abundant number, since it is smaller than the sum of its proper divisors (1181934132).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

656629980 is a wasteful number, since it uses less digits than its factorization.

656629980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10943845 (or 10943843 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 51.

The square root of 656629980 is about 25624.7922918411. The cubic root of 656629980 is about 869.1743521118.

The spelling of 656629980 in words is "six hundred fifty-six million, six hundred twenty-nine thousand, nine hundred eighty".