668636906256 has 60 divisors (see below), whose sum is σ = 2041368741360. Its totient is φ = 202617243840.

The previous prime is 668636906237. The next prime is 668636906263. The reversal of 668636906256 is 652609636866.

668636906256 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 668636906193 and 668636906202.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 211058046 + ... + 211061213.

It is an arithmetic number, because the mean of its divisors is an integer number (34022812356).

Almost surely, 2^668636906256 is an apocalyptic number.

668636906256 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

668636906256 is an abundant number, since it is smaller than the sum of its proper divisors (1372731835104).

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

668636906256 is a wasteful number, since it uses less digits than its factorization.

668636906256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422119284 (or 422119275 counting only the distinct ones).

The product of its (nonzero) digits is 100776960, while the sum is 63.

The spelling of 668636906256 in words is "six hundred sixty-eight billion, six hundred thirty-six million, nine hundred six thousand, two hundred fifty-six".