21646288086 has 32 divisors (see below), whose sum is σ = 44376571008. Its totient is φ = 7034986560.

The previous prime is 21646288031. The next prime is 21646288117. The reversal of 21646288086 is 68088264612.

It is a congruent number.

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, 373201 + ... + 427283.

It is an arithmetic number, because the mean of its divisors is an integer number (1386767844).

Almost surely, 2^21646288086 is an apocalyptic number.

21646288086 is an abundant number, since it is smaller than the sum of its proper divisors (22730282922).

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

21646288086 is a wasteful number, since it uses less digits than its factorization.

21646288086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55756.

The product of its (nonzero) digits is 1769472, while the sum is 51.

The spelling of 21646288086 in words is "twenty-one billion, six hundred forty-six million, two hundred eighty-eight thousand, eighty-six".