656839680 has 352 divisors, whose sum is σ = 2476051200. Its totient is φ = 145489920.

The previous prime is 656839679. The next prime is 656839691. The reversal of 656839680 is 86938656.

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, 4408246 + ... + 4408394.

Almost surely, 2^656839680 is an apocalyptic number.

656839680 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 656839680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1238025600).

656839680 is an abundant number, since it is smaller than the sum of its proper divisors (1819211520).

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

656839680 is a wasteful number, since it uses less digits than its factorization.

656839680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 207 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 51.

The square root of 656839680 is about 25628.8837056942. The cubic root of 656839680 is about 869.2668681752.

The spelling of 656839680 in words is "six hundred fifty-six million, eight hundred thirty-nine thousand, six hundred eighty".