13993991 has 8 divisors (see below), whose sum is σ = 15303168. Its totient is φ = 12691000.

The previous prime is 13993951. The next prime is 13993999. The reversal of 13993991 is 19939931.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13993991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13993999) 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, 4106 + ... + 6696.

It is an arithmetic number, because the mean of its divisors is an integer number (1912896).

Almost surely, 2^13993991 is an apocalyptic number.

13993991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

13993991 is a deficient number, since it is larger than the sum of its proper divisors (1309177).

13993991 is a wasteful number, since it uses less digits than its factorization.

13993991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3093.

The product of its digits is 59049, while the sum is 44.

The square root of 13993991 is about 3740.8543141908. The cubic root of 13993991 is about 240.9797392332.

The spelling of 13993991 in words is "thirteen million, nine hundred ninety-three thousand, nine hundred ninety-one".