13991237 has 8 divisors (see below), whose sum is σ = 15124704. Its totient is φ = 12865968.

The previous prime is 13991233. The next prime is 13991251. The reversal of 13991237 is 73219931.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13991237 - 2² = 13991233 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13991197 and 13991206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13991231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1778 + ... + 5580.

It is an arithmetic number, because the mean of its divisors is an integer number (1890588).

Almost surely, 2^13991237 is an apocalyptic number.

It is an amenable number.

13991237 is a deficient number, since it is larger than the sum of its proper divisors (1133467).

13991237 is a wasteful number, since it uses less digits than its factorization.

13991237 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4099.

The product of its digits is 10206, while the sum is 35.

The square root of 13991237 is about 3740.4861983437. The cubic root of 13991237 is about 240.9639300253.

The spelling of 13991237 in words is "thirteen million, nine hundred ninety-one thousand, two hundred thirty-seven".