13931687 has 32 divisors (see below), whose sum is σ = 19077120. Its totient is φ = 9838080.

The previous prime is 13931683. The next prime is 13931707. The reversal of 13931687 is 78613931.

13931687 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 13931687 - 2² = 13931683 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13931687.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13931681) 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, 37778 + ... + 38144.

It is an arithmetic number, because the mean of its divisors is an integer number (596160).

Almost surely, 2^13931687 is an apocalyptic number.

13931687 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

13931687 is a deficient number, since it is larger than the sum of its proper divisors (5145433).

13931687 is a wasteful number, since it uses less digits than its factorization.

13931687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431.

The product of its digits is 27216, while the sum is 38.

The square root of 13931687 is about 3732.5175150292. The cubic root of 13931687 is about 240.6215774405.

The spelling of 13931687 in words is "thirteen million, nine hundred thirty-one thousand, six hundred eighty-seven".