13911561 has 32 divisors (see below), whose sum is σ = 21648000. Its totient is φ = 8817984.

The previous prime is 13911539. The next prime is 13911571. The reversal of 13911561 is 16511931.

13911561 is a `hidden beast` number, since 13 + 91 + 1 + 561 = 666.

It is not a de Polignac number, because 13911561 - 2⁶ = 13911497 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (13911511) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 85266 + ... + 85428.

It is an arithmetic number, because the mean of its divisors is an integer number (676500).

Almost surely, 2^13911561 is an apocalyptic number.

It is an amenable number.

13911561 is a deficient number, since it is larger than the sum of its proper divisors (7736439).

13911561 is a wasteful number, since it uses less digits than its factorization.

13911561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310 (or 304 counting only the distinct ones).

The product of its digits is 810, while the sum is 27.

The square root of 13911561 is about 3729.8205050646. The cubic root of 13911561 is about 240.5056526493.

The spelling of 13911561 in words is "thirteen million, nine hundred eleven thousand, five hundred sixty-one".