656401536 has 256 divisors, whose sum is σ = 2269132800. Its totient is φ = 182891520.

The previous prime is 656401511. The next prime is 656401549. The reversal of 656401536 is 635104656.

656401536 is a `hidden beast` number, since 6 + 5 + 640 + 1 + 5 + 3 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 656401536.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1039941 + ... + 1040571.

It is an arithmetic number, because the mean of its divisors is an integer number (8863800).

Almost surely, 2^656401536 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 656401536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1134566400).

656401536 is an abundant number, since it is smaller than the sum of its proper divisors (1612731264).

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

656401536 is a wasteful number, since it uses less digits than its factorization.

656401536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 704 (or 686 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The square root of 656401536 is about 25620.3344240468. The cubic root of 656401536 is about 869.0735440959.

It can be divided in two parts, 65640 and 1536, that added together give a palindrome (67176).

The spelling of 656401536 in words is "six hundred fifty-six million, four hundred one thousand, five hundred thirty-six".