318328921 has 4 divisors (see below), whose sum is σ = 318419172. Its totient is φ = 318238672.

The previous prime is 318328909. The next prime is 318328931. The reversal of 318328921 is 129823813.

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

It can be written as a sum of positive squares in 2 ways, for example, as 135024400 + 183304521 = 11620^2 + 13539^2 .

It is a cyclic number.

It is not a de Polignac number, because 318328921 - 2⁵ = 318328889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (318328931) 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, 39610 + ... + 46963.

It is an arithmetic number, because the mean of its divisors is an integer number (79604793).

Almost surely, 2^318328921 is an apocalyptic number.

It is an amenable number.

318328921 is a deficient number, since it is larger than the sum of its proper divisors (90251).

318328921 is an equidigital number, since it uses as much as digits as its factorization.

318328921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90250.

The product of its digits is 20736, while the sum is 37.

The square root of 318328921 is about 17841.7746034412. The cubic root of 318328921 is about 682.7976730641.

The spelling of 318328921 in words is "three hundred eighteen million, three hundred twenty-eight thousand, nine hundred twenty-one".