21853853522172 has 36 divisors (see below), whose sum is σ = 63133354620336. Its totient is φ = 6243958149120.

The previous prime is 21853853522159. The next prime is 21853853522209. The reversal of 21853853522172 is 27122535835812.

21853853522172 is a `hidden beast` number, since 2 + 1 + 8 + 5 + 38 + 535 + 2 + 2 + 1 + 72 = 666.

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

It is a congruent number.

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, 43360820229 + ... + 43360820732.

Almost surely, 2^{21853853522172} is an apocalyptic number.

It is an amenable number.

21853853522172 is an abundant number, since it is smaller than the sum of its proper divisors (41279501098164).

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

21853853522172 is a wasteful number, since it uses less digits than its factorization.

21853853522172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86721640978 (or 86721640973 counting only the distinct ones).

The product of its digits is 8064000, while the sum is 54.

The spelling of 21853853522172 in words is "twenty-one trillion, eight hundred fifty-three billion, eight hundred fifty-three million, five hundred twenty-two thousand, one hundred seventy-two".