18391097 has 4 divisors (see below), whose sum is σ = 18422400. Its totient is φ = 18359796.

The previous prime is 18391019. The next prime is 18391123. The reversal of 18391097 is 79019381.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18391097 - 2¹² = 18387001 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18391097.

It is not an unprimeable number, because it can be changed into a prime (18391397) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14753 + ... + 15950.

It is an arithmetic number, because the mean of its divisors is an integer number (4605600).

Almost surely, 2^18391097 is an apocalyptic number.

It is an amenable number.

18391097 is a deficient number, since it is larger than the sum of its proper divisors (31303).

18391097 is an equidigital number, since it uses as much as digits as its factorization.

18391097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31302.

The product of its (nonzero) digits is 13608, while the sum is 38.

The square root of 18391097 is about 4288.4842310541. The cubic root of 18391097 is about 263.9586377271.

The spelling of 18391097 in words is "eighteen million, three hundred ninety-one thousand, ninety-seven".