21313318 has 32 divisors (see below), whose sum is σ = 37195200. Its totient is φ = 9077376.

The previous prime is 21313301. The next prime is 21313333. The reversal of 21313318 is 81331312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16728 + ... + 17956.

It is an arithmetic number, because the mean of its divisors is an integer number (1162350).

Almost surely, 2^21313318 is an apocalyptic number.

21313318 is a deficient number, since it is larger than the sum of its proper divisors (15881882).

21313318 is a wasteful number, since it uses less digits than its factorization.

21313318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1296.

The product of its digits is 432, while the sum is 22.

The square root of 21313318 is about 4616.6349216718. The cubic root of 21313318 is about 277.2577459937.

It can be divided in two parts, 213 and 13318, that added together give a palindrome (13531).

The spelling of 21313318 in words is "twenty-one million, three hundred thirteen thousand, three hundred eighteen".