21265499158560 has 72 divisors (see below), whose sum is σ = 72568515883500. Its totient is φ = 5670799775232.

The previous prime is 21265499158549. The next prime is 21265499158567. The reversal of 21265499158560 is 6585199456212.

21265499158560 is a `hidden beast` number, since 2 + 1 + 2 + 6 + 5 + 49 + 9 + 1 + 585 + 6 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 21265415765136 + 83393424 = 4611444^2 + 9132^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is not an unprimeable number, because it can be changed into a prime (21265499158567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7383852435 + ... + 7383855314.

Almost surely, 2^{21265499158560} is an apocalyptic number.

21265499158560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21265499158560 is an abundant number, since it is smaller than the sum of its proper divisors (51303016724940).

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

21265499158560 is a wasteful number, since it uses less digits than its factorization.

21265499158560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14767707770 (or 14767707759 counting only the distinct ones).

The product of its (nonzero) digits is 46656000, while the sum is 63.

The spelling of 21265499158560 in words is "twenty-one trillion, two hundred sixty-five billion, four hundred ninety-nine million, one hundred fifty-eight thousand, five hundred sixty".