13939209 has 14 divisors (see below), whose sum is σ = 20900346. Its totient is φ = 9292320.

The previous prime is 13939193. The next prime is 13939223. The reversal of 13939209 is 90293931.

It can be written as a sum of positive squares in only one way, i.e., 13483584 + 455625 = 3672^2 + 675^2 .

It is not a de Polignac number, because 13939209 - 2⁴ = 13939193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13939249) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 8832 + ... + 10289.

Almost surely, 2^13939209 is an apocalyptic number.

It is an amenable number.

13939209 is a deficient number, since it is larger than the sum of its proper divisors (6961137).

13939209 is an frugal number, since it uses more digits than its factorization.

13939209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19139 (or 19124 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 36.

The square root of 13939209 is about 3733.5250099604. The cubic root of 13939209 is about 240.6648751368.

The spelling of 13939209 in words is "thirteen million, nine hundred thirty-nine thousand, two hundred nine".