656098721280 has 640 divisors, whose sum is σ = 2510479319040. Its totient is φ = 161942077440.

The previous prime is 656098721269. The next prime is 656098721347. The reversal of 656098721280 is 82127890656.

656098721280 is a `hidden beast` number, since 6 + 5 + 609 + 8 + 7 + 2 + 1 + 28 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a super-2 number, since 2×656098721280² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 49275904 + ... + 49289216.

It is an arithmetic number, because the mean of its divisors is an integer number (3922623936).

Almost surely, 2^656098721280 is an apocalyptic number.

656098721280 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 656098721280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1255239659520).

656098721280 is an abundant number, since it is smaller than the sum of its proper divisors (1854380597760).

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

656098721280 is a wasteful number, since it uses less digits than its factorization.

656098721280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13399 (or 13377 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The spelling of 656098721280 in words is "six hundred fifty-six billion, ninety-eight million, seven hundred twenty-one thousand, two hundred eighty".