21660536525120 has 112 divisors (see below), whose sum is σ = 54928906141968. Its totient is φ = 8107418419200.

The previous prime is 21660536525093. The next prime is 21660536525141. The reversal of 21660536525120 is 2152563506612.

It can be written as a sum of positive squares in 8 ways, for example, as 5662648455424 + 15997888069696 = 2379632^2 + 3999736^2 .

It is a congruent number.

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, 10566731 + ... + 12448970.

Almost surely, 2^{21660536525120} is an apocalyptic number.

21660536525120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21660536525120 is an abundant number, since it is smaller than the sum of its proper divisors (33268369616848).

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

21660536525120 is a wasteful number, since it uses less digits than its factorization.

21660536525120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23015908 (or 23015898 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 44.

The spelling of 21660536525120 in words is "twenty-one trillion, six hundred sixty billion, five hundred thirty-six million, five hundred twenty-five thousand, one hundred twenty".