13656891 has 4 divisors (see below), whose sum is σ = 18209192. Its totient is φ = 9104592.

The previous prime is 13656887. The next prime is 13656901. The reversal of 13656891 is 19865631.

13656891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 13656891 - 2² = 13656887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13656821) 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, 2276146 + ... + 2276151.

It is an arithmetic number, because the mean of its divisors is an integer number (4552298).

Almost surely, 2^13656891 is an apocalyptic number.

13656891 is a deficient number, since it is larger than the sum of its proper divisors (4552301).

13656891 is an equidigital number, since it uses as much as digits as its factorization.

13656891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4552300.

The product of its digits is 38880, while the sum is 39.

The square root of 13656891 is about 3695.5231023497. The cubic root of 13656891 is about 239.0290109097.

It can be divided in two parts, 1365 and 6891, that added together give a triangular number (8256 = T₁₂₈).

The spelling of 13656891 in words is "thirteen million, six hundred fifty-six thousand, eight hundred ninety-one".