656221957776 has 240 divisors, whose sum is σ = 2328485253120. Its totient is φ = 167558158080.

The previous prime is 656221957771. The next prime is 656221957841. The reversal of 656221957776 is 677759122656.

656221957776 is a `hidden beast` number, since 6 + 56 + 2 + 2 + 1 + 9 + 577 + 7 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (656221957771) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 152641 + ... + 1155743.

It is an arithmetic number, because the mean of its divisors is an integer number (9702021888).

Almost surely, 2^656221957776 is an apocalyptic number.

656221957776 is a gapful number since it is divisible by the number (66) 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 656221957776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1164242626560).

656221957776 is an abundant number, since it is smaller than the sum of its proper divisors (1672263295344).

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

656221957776 is a wasteful number, since it uses less digits than its factorization.

656221957776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1003194 (or 1003185 counting only the distinct ones).

The product of its digits is 66679200, while the sum is 63.

The spelling of 656221957776 in words is "six hundred fifty-six billion, two hundred twenty-one million, nine hundred fifty-seven thousand, seven hundred seventy-six".