13999431 has 16 divisors (see below), whose sum is σ = 19836000. Its totient is φ = 8765568.

The previous prime is 13999423. The next prime is 13999441. The reversal of 13999431 is 13499931.

13999431 = 89² + 90² + ... + 349².

13999431 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 13999431 - 2³ = 13999423 is a prime.

It is a super-3 number, since 3×13999431³ (a number of 22 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 13999431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13999421) 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, 1045 + ... + 5393.

It is an arithmetic number, because the mean of its divisors is an integer number (1239750).

Almost surely, 2^13999431 is an apocalyptic number.

13999431 is a deficient number, since it is larger than the sum of its proper divisors (5836569).

13999431 is a wasteful number, since it uses less digits than its factorization.

13999431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4418.

The product of its digits is 26244, while the sum is 39.

The square root of 13999431 is about 3741.5813501780. The cubic root of 13999431 is about 241.0109612044.

Subtracting from 13999431 its reverse (13499931), we obtain a triangular number (499500 = T₉₉₉).

The spelling of 13999431 in words is "thirteen million, nine hundred ninety-nine thousand, four hundred thirty-one".