13538727621 has 24 divisors (see below), whose sum is σ = 19875265280. Its totient is φ = 8879266656.

The previous prime is 13538727607. The next prime is 13538727649. The reversal of 13538727621 is 12672783531.

13538727621 is a `hidden beast` number, since 1 + 353 + 8 + 7 + 276 + 21 = 666.

It is not a de Polignac number, because 13538727621 - 2⁵ = 13538727589 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 (13538727421) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 162576 + ... + 231318.

Almost surely, 2^13538727621 is an apocalyptic number.

It is an amenable number.

13538727621 is a deficient number, since it is larger than the sum of its proper divisors (6336537659).

13538727621 is a wasteful number, since it uses less digits than its factorization.

13538727621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69105 (or 69102 counting only the distinct ones).

The product of its digits is 423360, while the sum is 45.

The spelling of 13538727621 in words is "thirteen billion, five hundred thirty-eight million, seven hundred twenty-seven thousand, six hundred twenty-one".