18317312 has 64 divisors (see below), whose sum is σ = 40369560. Its totient is φ = 8257536.

The previous prime is 18317309. The next prime is 18317323. The reversal of 18317312 is 21371381.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 425963 + ... + 426005.

Almost surely, 2^18317312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18317312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20184780).

18317312 is an abundant number, since it is smaller than the sum of its proper divisors (22052248).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18317312 is an frugal number, since it uses more digits than its factorization.

18317312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 58 counting only the distinct ones).

The product of its digits is 1008, while the sum is 26.

The square root of 18317312 is about 4279.8728953089. The cubic root of 18317312 is about 263.6051642970.

Adding to 18317312 its reverse (21371381), we get a palindrome (39688693).

The spelling of 18317312 in words is "eighteen million, three hundred seventeen thousand, three hundred twelve".