656985709440 has 96 divisors (see below), whose sum is σ = 2268653797800. Its totient is φ = 175196187648.

The previous prime is 656985709381. The next prime is 656985709463. The reversal of 656985709440 is 44907589656.

656985709440 is a `hidden beast` number, since 6 + 56 + 9 + 8 + 570 + 9 + 4 + 4 + 0 = 666.

656985709440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a super-2 number, since 2×656985709440² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

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, 57024250 + ... + 57035769.

Almost surely, 2^656985709440 is an apocalyptic number.

656985709440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

656985709440 is an abundant number, since it is smaller than the sum of its proper divisors (1611668088360).

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

656985709440 is a wasteful number, since it uses less digits than its factorization.

656985709440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114060044 (or 114060029 counting only the distinct ones).

The product of its (nonzero) digits is 65318400, while the sum is 63.

The spelling of 656985709440 in words is "six hundred fifty-six billion, nine hundred eighty-five million, seven hundred nine thousand, four hundred forty".