21116808980 has 12 divisors (see below), whose sum is σ = 44345298900. Its totient is φ = 8446723584.

The previous prime is 21116808959. The next prime is 21116809009. The reversal of 21116808980 is 8980861112.

It can be written as a sum of positive squares in 2 ways, for example, as 7233842704 + 13882966276 = 85052^2 + 117826^2 .

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, 527920205 + ... + 527920244.

It is an arithmetic number, because the mean of its divisors is an integer number (3695441575).

Almost surely, 2^21116808980 is an apocalyptic number.

21116808980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21116808980 is an abundant number, since it is smaller than the sum of its proper divisors (23228489920).

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

21116808980 is a wasteful number, since it uses less digits than its factorization.

21116808980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1055840458 (or 1055840456 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 44.

The spelling of 21116808980 in words is "twenty-one billion, one hundred sixteen million, eight hundred eight thousand, nine hundred eighty".