13878239 has 4 divisors (see below), whose sum is σ = 14694624. Its totient is φ = 13061856.

The previous prime is 13878229. The next prime is 13878281. The reversal of 13878239 is 93287831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13878239 is a prime.

It is a super-2 number, since 2×13878239² = 385211035482242, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13878196 and 13878205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13878229) 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, 408167 + ... + 408200.

It is an arithmetic number, because the mean of its divisors is an integer number (3673656).

Almost surely, 2^13878239 is an apocalyptic number.

13878239 is a deficient number, since it is larger than the sum of its proper divisors (816385).

13878239 is an equidigital number, since it uses as much as digits as its factorization.

13878239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 816384.

The product of its digits is 72576, while the sum is 41.

The square root of 13878239 is about 3725.3508559597. The cubic root of 13878239 is about 240.3134734835.

The spelling of 13878239 in words is "thirteen million, eight hundred seventy-eight thousand, two hundred thirty-nine".