18872109 has 24 divisors (see below), whose sum is σ = 29047200. Its totient is φ = 12235536.

The previous prime is 18872093. The next prime is 18872123. The reversal of 18872109 is 90127881.

It is not a de Polignac number, because 18872109 - 2⁴ = 18872093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18872209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7942 + ... + 10040.

It is an arithmetic number, because the mean of its divisors is an integer number (1210300).

Almost surely, 2^18872109 is an apocalyptic number.

It is an amenable number.

18872109 is a deficient number, since it is larger than the sum of its proper divisors (10175091).

18872109 is an equidigital number, since it uses as much as digits as its factorization.

18872109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2151 (or 2139 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 18872109 is about 4344.2040697923. The cubic root of 18872109 is about 266.2401067540.

It can be divided in two parts, 18872 and 109, that added together give a palindrome (18981).

The spelling of 18872109 in words is "eighteen million, eight hundred seventy-two thousand, one hundred nine".