656608640672 has 24 divisors (see below), whose sum is σ = 1295683734996. Its totient is φ = 327546104832.

The previous prime is 656608640629. The next prime is 656608640689. The reversal of 656608640672 is 276046806656.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 647645095696 + 8963544976 = 804764^2 + 94676^2 .

It is a super-3 number, since 3×656608640672³ (a number of 36 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 23680163 + ... + 23707874.

Almost surely, 2^656608640672 is an apocalyptic number.

It is an amenable number.

656608640672 is a deficient number, since it is larger than the sum of its proper divisors (639075094324).

656608640672 is a wasteful number, since it uses less digits than its factorization.

656608640672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47388480 (or 47388472 counting only the distinct ones).

The product of its (nonzero) digits is 17418240, while the sum is 56.

The spelling of 656608640672 in words is "six hundred fifty-six billion, six hundred eight million, six hundred forty thousand, six hundred seventy-two".