13685991 has 16 divisors (see below), whose sum is σ = 19968768. Its totient is φ = 8268800.

The previous prime is 13685981. The next prime is 13685993. The reversal of 13685991 is 19958631.

It is a cyclic number.

It is not a de Polignac number, because 13685991 - 2⁶ = 13685927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13685993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20830 + ... + 21476.

It is an arithmetic number, because the mean of its divisors is an integer number (1248048).

Almost surely, 2^13685991 is an apocalyptic number.

13685991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

13685991 is a deficient number, since it is larger than the sum of its proper divisors (6282777).

13685991 is a wasteful number, since it uses less digits than its factorization.

13685991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1302.

The product of its digits is 58320, while the sum is 42.

The square root of 13685991 is about 3699.4582035752. The cubic root of 13685991 is about 239.1986642040.

The spelling of 13685991 in words is "thirteen million, six hundred eighty-five thousand, nine hundred ninety-one".