21555160256 has 112 divisors (see below), whose sum is σ = 50172713472. Its totient is φ = 8995276800.

The previous prime is 21555160213. The next prime is 21555160273. The reversal of 21555160256 is 65206155512.

It is a tau number, because it is divible by the number of its divisors (112).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14895725 + ... + 14897171.

It is an arithmetic number, because the mean of its divisors is an integer number (447970656).

Almost surely, 2^21555160256 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 21555160256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25086356736).

21555160256 is an abundant number, since it is smaller than the sum of its proper divisors (28617553216).

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

21555160256 is a wasteful number, since it uses less digits than its factorization.

21555160256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2318 (or 2308 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 38.

The spelling of 21555160256 in words is "twenty-one billion, five hundred fifty-five million, one hundred sixty thousand, two hundred fifty-six".