18813139 has 4 divisors (see below), whose sum is σ = 19051360. Its totient is φ = 18574920.

The previous prime is 18813133. The next prime is 18813161. The reversal of 18813139 is 93131881.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18813139 - 2⁵ = 18813107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18813133) 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, 118992 + ... + 119149.

It is an arithmetic number, because the mean of its divisors is an integer number (4762840).

Almost surely, 2^18813139 is an apocalyptic number.

18813139 is a deficient number, since it is larger than the sum of its proper divisors (238221).

18813139 is an equidigital number, since it uses as much as digits as its factorization.

18813139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238220.

The product of its digits is 5184, while the sum is 34.

The square root of 18813139 is about 4337.4115552942. The cubic root of 18813139 is about 265.9625090848.

The spelling of 18813139 in words is "eighteen million, eight hundred thirteen thousand, one hundred thirty-nine".