18085919 has 4 divisors (see below), whose sum is σ = 18392520. Its totient is φ = 17779320.

The previous prime is 18085897. The next prime is 18085931. The reversal of 18085919 is 91958081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91958081 = 19 ⋅4839899.

It is a cyclic number.

It is not a de Polignac number, because 18085919 - 2²⁰ = 17037343 is a prime.

It is a super-2 number, since 2×18085919² = 654200932149122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18085019) 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, 153212 + ... + 153329.

It is an arithmetic number, because the mean of its divisors is an integer number (4598130).

Almost surely, 2^18085919 is an apocalyptic number.

18085919 is a deficient number, since it is larger than the sum of its proper divisors (306601).

18085919 is an equidigital number, since it uses as much as digits as its factorization.

18085919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306600.

The product of its (nonzero) digits is 25920, while the sum is 41.

The square root of 18085919 is about 4252.7542839906. The cubic root of 18085919 is about 262.4904619361.

The spelling of 18085919 in words is "eighteen million, eighty-five thousand, nine hundred nineteen".