21655255464 has 48 divisors (see below), whose sum is σ = 59009496000. Its totient is φ = 7174129824.

The previous prime is 21655255441. The next prime is 21655255493. The reversal of 21655255464 is 46455255612.

21655255464 is a `hidden beast` number, since 2 + 1 + 6 + 552 + 55 + 46 + 4 = 666.

It is a super-2 number, since 2×21655255464² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 910864 + ... + 934335.

It is an arithmetic number, because the mean of its divisors is an integer number (1229364500).

Almost surely, 2^21655255464 is an apocalyptic number.

21655255464 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21655255464 is an abundant number, since it is smaller than the sum of its proper divisors (37354240536).

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

21655255464 is a wasteful number, since it uses less digits than its factorization.

21655255464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1845374 (or 1845367 counting only the distinct ones).

The product of its digits is 1440000, while the sum is 45.

The spelling of 21655255464 in words is "twenty-one billion, six hundred fifty-five million, two hundred fifty-five thousand, four hundred sixty-four".