18939109 has 8 divisors (see below), whose sum is σ = 22343168. Its totient is φ = 15709680.

The previous prime is 18939103. The next prime is 18939113. The reversal of 18939109 is 90193981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-18939109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18939103) 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, 43422 + ... + 43855.

It is an arithmetic number, because the mean of its divisors is an integer number (2792896).

Almost surely, 2^18939109 is an apocalyptic number.

It is an amenable number.

18939109 is a deficient number, since it is larger than the sum of its proper divisors (3404059).

18939109 is an equidigital number, since it uses as much as digits as its factorization.

18939109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87315.

The product of its (nonzero) digits is 17496, while the sum is 40.

The square root of 18939109 is about 4351.9086617253. The cubic root of 18939109 is about 266.5548042974.

The spelling of 18939109 in words is "eighteen million, nine hundred thirty-nine thousand, one hundred nine".