18119891 has 8 divisors (see below), whose sum is σ = 18392640. Its totient is φ = 17849088.

The previous prime is 18119887. The next prime is 18119897. The reversal of 18119891 is 19891181.

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 18119891 - 2² = 18119887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18119897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35345 + ... + 35853.

It is an arithmetic number, because the mean of its divisors is an integer number (2299080).

Almost surely, 2^18119891 is an apocalyptic number.

18119891 is a deficient number, since it is larger than the sum of its proper divisors (272749).

18119891 is an equidigital number, since it uses as much as digits as its factorization.

18119891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 973.

The product of its digits is 5184, while the sum is 38.

The square root of 18119891 is about 4256.7465275724. The cubic root of 18119891 is about 262.6547103118.

The spelling of 18119891 in words is "eighteen million, one hundred nineteen thousand, eight hundred ninety-one".