13887639 has 8 divisors (see below), whose sum is σ = 20574320. Its totient is φ = 9258408.

The previous prime is 13887611. The next prime is 13887641. The reversal of 13887639 is 93678831.

It is a happy number.

13887639 is a `hidden beast` number, since 1 + 3 + 8 + 8 + 7 + 639 = 666.

It is not a de Polignac number, because 13887639 - 2⁹ = 13887127 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13887594 and 13887603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13887539) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 257152 + ... + 257205.

It is an arithmetic number, because the mean of its divisors is an integer number (2571790).

Almost surely, 2^13887639 is an apocalyptic number.

13887639 is a deficient number, since it is larger than the sum of its proper divisors (6686681).

13887639 is an equidigital number, since it uses as much as digits as its factorization.

13887639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514366 (or 514360 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 13887639 is about 3726.6122685356. The cubic root of 13887639 is about 240.3677175614.

The spelling of 13887639 in words is "thirteen million, eight hundred eighty-seven thousand, six hundred thirty-nine".