21555523344 has 40 divisors (see below), whose sum is σ = 57190109440. Its totient is φ = 6990979968.

The previous prime is 21555523331. The next prime is 21555523357. The reversal of 21555523344 is 44332555512.

It is an interprime number because it is at equal distance from previous prime (21555523331) and next prime (21555523357).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6066784 + ... + 6070335.

It is an arithmetic number, because the mean of its divisors is an integer number (1429752736).

Almost surely, 2^21555523344 is an apocalyptic number.

21555523344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21555523344 is an abundant number, since it is smaller than the sum of its proper divisors (35634586096).

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

21555523344 is a wasteful number, since it uses less digits than its factorization.

21555523344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12137167 (or 12137161 counting only the distinct ones).

The product of its digits is 360000, while the sum is 39.

The spelling of 21555523344 in words is "twenty-one billion, five hundred fifty-five million, five hundred twenty-three thousand, three hundred forty-four".