13878391 has 2 divisors, whose sum is σ = 13878392. Its totient is φ = 13878390.

The previous prime is 13878383. The next prime is 13878413. The reversal of 13878391 is 19387831.

13878391 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is an emirp because it is prime and its reverse (19387831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13878391 - 2³ = 13878383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13878311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6939195 + 6939196.

It is an arithmetic number, because the mean of its divisors is an integer number (6939196).

Almost surely, 2^13878391 is an apocalyptic number.

13878391 is a deficient number, since it is larger than the sum of its proper divisors (1).

13878391 is an equidigital number, since it uses as much as digits as its factorization.

13878391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 40.

The square root of 13878391 is about 3725.3712566669. The cubic root of 13878391 is about 240.3143508166.

The spelling of 13878391 in words is "thirteen million, eight hundred seventy-eight thousand, three hundred ninety-one".