13858991 has 4 divisors (see below), whose sum is σ = 14014800. Its totient is φ = 13703184.

The previous prime is 13858981. The next prime is 13858993. The reversal of 13858991 is 19985831.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 13858991 - 2¹⁰ = 13857967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13858993) 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, 77771 + ... + 77948.

It is an arithmetic number, because the mean of its divisors is an integer number (3503700).

Almost surely, 2^13858991 is an apocalyptic number.

13858991 is a deficient number, since it is larger than the sum of its proper divisors (155809).

13858991 is an equidigital number, since it uses as much as digits as its factorization.

13858991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155808.

The product of its digits is 77760, while the sum is 44.

The square root of 13858991 is about 3722.7665787691. The cubic root of 13858991 is about 240.2023236032.

The spelling of 13858991 in words is "thirteen million, eight hundred fifty-eight thousand, nine hundred ninety-one".