21756514440 has 64 divisors (see below), whose sum is σ = 66055953600. Its totient is φ = 5731834112.

The previous prime is 21756514349. The next prime is 21756514459. The reversal of 21756514440 is 4441565712.

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, 1082235 + ... + 1102154.

It is an arithmetic number, because the mean of its divisors is an integer number (1032124275).

Almost surely, 2^21756514440 is an apocalyptic number.

21756514440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21756514440 is an abundant number, since it is smaller than the sum of its proper divisors (44299439160).

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

21756514440 is a wasteful number, since it uses less digits than its factorization.

21756514440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2184486 (or 2184482 counting only the distinct ones).

The product of its (nonzero) digits is 134400, while the sum is 39.

The spelling of 21756514440 in words is "twenty-one billion, seven hundred fifty-six million, five hundred fourteen thousand, four hundred forty".