211638304656 has 100 divisors (see below), whose sum is σ = 612926618524. Its totient is φ = 70501881600.

The previous prime is 211638304639. The next prime is 211638304687. The reversal of 211638304656 is 656403836112.

211638304656 is a `hidden beast` number, since 2 + 1 + 1 + 638 + 3 + 0 + 4 + 6 + 5 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 130118918400 + 81519386256 = 360720^2 + 285516^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2050446 + ... + 2151186.

Almost surely, 2^211638304656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211638304656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (306463309262).

211638304656 is an abundant number, since it is smaller than the sum of its proper divisors (401288313868).

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

211638304656 is a wasteful number, since it uses less digits than its factorization.

211638304656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102382 (or 102367 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 211638304656 in words is "two hundred eleven billion, six hundred thirty-eight million, three hundred four thousand, six hundred fifty-six".