656621678880 has 960 divisors, whose sum is σ = 2556105818112. Its totient is φ = 158018273280.

The previous prime is 656621678873. The next prime is 656621678891. The reversal of 656621678880 is 88876126656.

656621678880 is a `hidden beast` number, since 6 + 566 + 2 + 1 + 67 + 8 + 8 + 8 + 0 = 666.

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 159 ways as a sum of consecutive naturals, for example, 867399462 + ... + 867400218.

Almost surely, 2^656621678880 is an apocalyptic number.

656621678880 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 656621678880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1278052909056).

656621678880 is an abundant number, since it is smaller than the sum of its proper divisors (1899484139232).

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

656621678880 is a wasteful number, since it uses less digits than its factorization.

656621678880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 959 (or 942 counting only the distinct ones).

The product of its (nonzero) digits is 46448640, while the sum is 63.

The spelling of 656621678880 in words is "six hundred fifty-six billion, six hundred twenty-one million, six hundred seventy-eight thousand, eight hundred eighty".