21856627280 has 30 divisors (see below), whose sum is σ = 50819733006. Its totient is φ = 8742121984.

The previous prime is 21856627253. The next prime is 21856627301. The reversal of 21856627280 is 8272665812.

It can be written as a sum of positive squares in 3 ways, for example, as 11132782144 + 10723845136 = 105512^2 + 103556^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1314056 + ... + 1330584.

Almost surely, 2^21856627280 is an apocalyptic number.

21856627280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21856627280 is an abundant number, since it is smaller than the sum of its proper divisors (28963105726).

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

21856627280 is an frugal number, since it uses more digits than its factorization.

21856627280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33071 (or 16536 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 47.

The spelling of 21856627280 in words is "twenty-one billion, eight hundred fifty-six million, six hundred twenty-seven thousand, two hundred eighty".