18393139 has 4 divisors (see below), whose sum is σ = 18438520. Its totient is φ = 18347760.

The previous prime is 18393131. The next prime is 18393157. The reversal of 18393139 is 93139381.

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 18393139 - 2³ = 18393131 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18393098 and 18393107.

It is not an unprimeable number, because it can be changed into a prime (18393131) 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, 22077 + ... + 22894.

It is an arithmetic number, because the mean of its divisors is an integer number (4609630).

Almost surely, 2^18393139 is an apocalyptic number.

18393139 is a deficient number, since it is larger than the sum of its proper divisors (45381).

18393139 is an equidigital number, since it uses as much as digits as its factorization.

18393139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45380.

The product of its digits is 17496, while the sum is 37.

The square root of 18393139 is about 4288.7223039036. The cubic root of 18393139 is about 263.9684066494.

The spelling of 18393139 in words is "eighteen million, three hundred ninety-three thousand, one hundred thirty-nine".