18319318 has 4 divisors (see below), whose sum is σ = 27478980. Its totient is φ = 9159658.

The previous prime is 18319309. The next prime is 18319321. The reversal of 18319318 is 81391381.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81391381 = 193 ⋅421717.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4579828 + ... + 4579831.

It is an arithmetic number, because the mean of its divisors is an integer number (6869745).

Almost surely, 2^18319318 is an apocalyptic number.

18319318 is a deficient number, since it is larger than the sum of its proper divisors (9159662).

18319318 is an equidigital number, since it uses as much as digits as its factorization.

18319318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9159661.

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

The square root of 18319318 is about 4280.1072416471. The cubic root of 18319318 is about 263.6147867543.

The spelling of 18319318 in words is "eighteen million, three hundred nineteen thousand, three hundred eighteen".