21331318 has 8 divisors (see below), whose sum is σ = 32021712. Its totient is φ = 10657416.

The previous prime is 21331313. The next prime is 21331333. The reversal of 21331318 is 81313312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331313) 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, 105 + ... + 6532.

It is an arithmetic number, because the mean of its divisors is an integer number (4002714).

Almost surely, 2^21331318 is an apocalyptic number.

21331318 is a deficient number, since it is larger than the sum of its proper divisors (10690394).

21331318 is a wasteful number, since it uses less digits than its factorization.

21331318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8246.

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

The square root of 21331318 is about 4618.5839821313. The cubic root of 21331318 is about 277.3357760022.

The spelling of 21331318 in words is "twenty-one million, three hundred thirty-one thousand, three hundred eighteen".