13909731 has 16 divisors (see below), whose sum is σ = 20886528. Its totient is φ = 8157600.

The previous prime is 13909717. The next prime is 13909741. The reversal of 13909731 is 13790931.

It is not a de Polignac number, because 13909731 - 2⁵ = 13909699 is a prime.

It is a super-2 number, since 2×13909731² = 386961232984722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 13909692 and 13909701.

It is not an unprimeable number, because it can be changed into a prime (13909741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5776 + ... + 7821.

It is an arithmetic number, because the mean of its divisors is an integer number (1305408).

Almost surely, 2^13909731 is an apocalyptic number.

13909731 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

13909731 is a deficient number, since it is larger than the sum of its proper divisors (6976797).

13909731 is a wasteful number, since it uses less digits than its factorization.

13909731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13642.

The product of its (nonzero) digits is 5103, while the sum is 33.

The square root of 13909731 is about 3729.5751768801. The cubic root of 13909731 is about 240.4951063935.

It can be divided in two parts, 139097 and 31, that added together give a triangular number (139128 = T₅₂₇).

The spelling of 13909731 in words is "thirteen million, nine hundred nine thousand, seven hundred thirty-one".