656778121208 has 16 divisors (see below), whose sum is σ = 1343409793560. Its totient is φ = 298535509600.

The previous prime is 656778121177. The next prime is 656778121211. The reversal of 656778121208 is 802121877656.

It is a self number, because there is not a number n which added to its sum of digits gives 656778121208.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3731693783 + ... + 3731693958.

Almost surely, 2^656778121208 is an apocalyptic number.

It is an amenable number.

656778121208 is an abundant number, since it is smaller than the sum of its proper divisors (686631672352).

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

656778121208 is a wasteful number, since it uses less digits than its factorization.

656778121208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7463387758 (or 7463387754 counting only the distinct ones).

The product of its (nonzero) digits is 2257920, while the sum is 53.

The spelling of 656778121208 in words is "six hundred fifty-six billion, seven hundred seventy-eight million, one hundred twenty-one thousand, two hundred eight".