13639728 has 20 divisors (see below), whose sum is σ = 35236088. Its totient is φ = 4546560.

The previous prime is 13639727. The next prime is 13639733. The reversal of 13639728 is 82793631.

It is not an unprimeable number, because it can be changed into a prime (13639727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142033 + ... + 142128.

Almost surely, 2^13639728 is an apocalyptic number.

It is an amenable number.

13639728 is an abundant number, since it is smaller than the sum of its proper divisors (21596360).

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

13639728 is a wasteful number, since it uses less digits than its factorization.

13639728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284172 (or 284166 counting only the distinct ones).

The product of its digits is 54432, while the sum is 39.

The square root of 13639728 is about 3693.2002382757. The cubic root of 13639728 is about 238.9288374351.

The spelling of 13639728 in words is "thirteen million, six hundred thirty-nine thousand, seven hundred twenty-eight".