13520660021 has 16 divisors (see below), whose sum is σ = 14907086208. Its totient is φ = 12160632000.

The previous prime is 13520660017. The next prime is 13520660051. The reversal of 13520660021 is 12006602531.

It is not a de Polignac number, because 13520660021 - 2² = 13520660017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13520660051) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1781591 + ... + 1789163.

It is an arithmetic number, because the mean of its divisors is an integer number (931692888).

Almost surely, 2^13520660021 is an apocalyptic number.

13520660021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

13520660021 is a deficient number, since it is larger than the sum of its proper divisors (1386426187).

13520660021 is a wasteful number, since it uses less digits than its factorization.

13520660021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9292.

The product of its (nonzero) digits is 2160, while the sum is 26.

The spelling of 13520660021 in words is "thirteen billion, five hundred twenty million, six hundred sixty thousand, twenty-one".