13931720 has 32 divisors (see below), whose sum is σ = 34197120. Its totient is φ = 5065920.

The previous prime is 13931717. The next prime is 13931737. The reversal of 13931720 is 2713931.

It is a self number, because there is not a number n which added to its sum of digits gives 13931720.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15392 + ... + 16271.

It is an arithmetic number, because the mean of its divisors is an integer number (1068660).

Almost surely, 2^13931720 is an apocalyptic number.

13931720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13931720 is an abundant number, since it is smaller than the sum of its proper divisors (20265400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13931720 is a wasteful number, since it uses less digits than its factorization.

13931720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31685 (or 31681 counting only the distinct ones).

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 13931720 is about 3732.5219356355. The cubic root of 13931720 is about 240.6217674272.

It can be divided in two parts, 1393 and 1720, that added together give a palindrome (3113).

The spelling of 13931720 in words is "thirteen million, nine hundred thirty-one thousand, seven hundred twenty".