656179920 has 160 divisors (see below), whose sum is σ = 2465735040. Its totient is φ = 159068160.

The previous prime is 656179919. The next prime is 656179933. The reversal of 656179920 is 29971656.

It is a happy number.

656179920 is a `hidden beast` number, since 6 + 5 + 617 + 9 + 9 + 20 = 666.

It is a super-2 number, since 2×656179920² = 861144174822412800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

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, 9952 + ... + 37568.

It is an arithmetic number, because the mean of its divisors is an integer number (15410844).

Almost surely, 2^656179920 is an apocalyptic number.

656179920 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 656179920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1232867520).

656179920 is an abundant number, since it is smaller than the sum of its proper divisors (1809555120).

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

656179920 is a wasteful number, since it uses less digits than its factorization.

656179920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27650 (or 27638 counting only the distinct ones).

The product of its (nonzero) digits is 204120, while the sum is 45.

The square root of 656179920 is about 25616.0090568379. The cubic root of 656179920 is about 868.9757267938.

The spelling of 656179920 in words is "six hundred fifty-six million, one hundred seventy-nine thousand, nine hundred twenty".