13718991 has 32 divisors (see below), whose sum is σ = 21756672. Its totient is φ = 7580160.

The previous prime is 13718989. The next prime is 13719029. The reversal of 13718991 is 19981731.

It is not a de Polignac number, because 13718991 - 2¹ = 13718989 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13718941) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 48336 + ... + 48618.

It is an arithmetic number, because the mean of its divisors is an integer number (679896).

Almost surely, 2^13718991 is an apocalyptic number.

13718991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

13718991 is a deficient number, since it is larger than the sum of its proper divisors (8037681).

13718991 is a wasteful number, since it uses less digits than its factorization.

13718991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423.

The product of its digits is 13608, while the sum is 39.

The square root of 13718991 is about 3703.9156307886. The cubic root of 13718991 is about 239.3907637999.

The spelling of 13718991 in words is "thirteen million, seven hundred eighteen thousand, nine hundred ninety-one".