656543961572 has 12 divisors (see below), whose sum is σ = 1148961488556. Its totient is φ = 328269250560.

The previous prime is 656543961529. The next prime is 656543961583. The reversal of 656543961572 is 275169345656.

It can be written as a sum of positive squares in 2 ways, for example, as 493219671616 + 163324289956 = 702296^2 + 404134^2 .

It is a super-2 number, since 2×656543961572² (a number of 24 digits) contains 22 as substring.

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, 82973 + ... + 1148900.

It is an arithmetic number, because the mean of its divisors is an integer number (95746790713).

Almost surely, 2^656543961572 is an apocalyptic number.

It is an amenable number.

656543961572 is a deficient number, since it is larger than the sum of its proper divisors (492417526984).

656543961572 is a wasteful number, since it uses less digits than its factorization.

656543961572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1365118 (or 1365116 counting only the distinct ones).

The product of its digits is 40824000, while the sum is 59.

The spelling of 656543961572 in words is "six hundred fifty-six billion, five hundred forty-three million, nine hundred sixty-one thousand, five hundred seventy-two".