657968638212 has 36 divisors (see below), whose sum is σ = 1688022366576. Its totient is φ = 216049402800.

The previous prime is 657968638207. The next prime is 657968638267. The reversal of 657968638212 is 212836869756.

It is a happy number.

657968638212 is a `hidden beast` number, since 6 + 579 + 6 + 8 + 6 + 38 + 21 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 657968638212.

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, 136392414 + ... + 136397237.

Almost surely, 2^657968638212 is an apocalyptic number.

It is an amenable number.

657968638212 is an abundant number, since it is smaller than the sum of its proper divisors (1030053728364).

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

657968638212 is a wasteful number, since it uses less digits than its factorization.

657968638212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272789728 (or 272789723 counting only the distinct ones).

The product of its digits is 52254720, while the sum is 63.

The spelling of 657968638212 in words is "six hundred fifty-seven billion, nine hundred sixty-eight million, six hundred thirty-eight thousand, two hundred twelve".