21275888180 has 12 divisors (see below), whose sum is σ = 44679365220. Its totient is φ = 8510355264.

The previous prime is 21275888047. The next prime is 21275888197. The reversal of 21275888180 is 8188857212.

It can be written as a sum of positive squares in 2 ways, for example, as 15337336336 + 5938551844 = 123844^2 + 77062^2 .

It is a hoax number, since the sum of its digits (50) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 531897185 + ... + 531897224.

It is an arithmetic number, because the mean of its divisors is an integer number (3723280435).

Almost surely, 2^21275888180 is an apocalyptic number.

21275888180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21275888180 is an abundant number, since it is smaller than the sum of its proper divisors (23403477040).

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

21275888180 is a wasteful number, since it uses less digits than its factorization.

21275888180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1063794418 (or 1063794416 counting only the distinct ones).

The product of its (nonzero) digits is 573440, while the sum is 50.

The spelling of 21275888180 in words is "twenty-one billion, two hundred seventy-five million, eight hundred eighty-eight thousand, one hundred eighty".