18508919 has 16 divisors (see below), whose sum is σ = 22063104. Its totient is φ = 15304800.

The previous prime is 18508913. The next prime is 18508921. The reversal of 18508919 is 91980581.

It is a cyclic number.

It is not a de Polignac number, because 18508919 - 2²⁴ = 1731703 is a prime.

It is a super-4 number, since 4×18508919⁴ (a number of 30 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18508913) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9242 + ... + 11064.

It is an arithmetic number, because the mean of its divisors is an integer number (1378944).

Almost surely, 2^18508919 is an apocalyptic number.

18508919 is a deficient number, since it is larger than the sum of its proper divisors (3554185).

18508919 is a wasteful number, since it uses less digits than its factorization.

18508919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1918.

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

The square root of 18508919 is about 4302.1993212774. The cubic root of 18508919 is about 264.5211192359.

The spelling of 18508919 in words is "eighteen million, five hundred eight thousand, nine hundred nineteen".