21606364188 has 36 divisors (see below), whose sum is σ = 54823777008. Its totient is φ = 7174733760.

The previous prime is 21606364187. The next prime is 21606364259. The reversal of 21606364188 is 88146360612.

21606364188 is a `hidden beast` number, since 2 + 1 + 6 + 0 + 636 + 4 + 1 + 8 + 8 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21606364181) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1131553 + ... + 1150488.

Almost surely, 2^21606364188 is an apocalyptic number.

It is an amenable number.

21606364188 is an abundant number, since it is smaller than the sum of its proper divisors (33217412820).

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

21606364188 is a wasteful number, since it uses less digits than its factorization.

21606364188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2282314 (or 2282309 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The spelling of 21606364188 in words is "twenty-one billion, six hundred six million, three hundred sixty-four thousand, one hundred eighty-eight".