656576640 has 96 divisors (see below), whose sum is σ = 2267261100. Its totient is φ = 175085568.

The previous prime is 656576639. The next prime is 656576719. The reversal of 656576640 is 46675656.

It can be written as a sum of positive squares in 2 ways, for example, as 631416384 + 25160256 = 25128^2 + 5016^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 51235 + ... + 62754.

Almost surely, 2^656576640 is an apocalyptic number.

656576640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

656576640 is an abundant number, since it is smaller than the sum of its proper divisors (1610684460).

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

656576640 is a wasteful number, since it uses less digits than its factorization.

656576640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114014 (or 113999 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 45.

The square root of 656576640 is about 25623.7514817796. The cubic root of 656576640 is about 869.1508162714.

The spelling of 656576640 in words is "six hundred fifty-six million, five hundred seventy-six thousand, six hundred forty".