21318522 has 8 divisors (see below), whose sum is σ = 42637056. Its totient is φ = 7106172.

The previous prime is 21318511. The next prime is 21318533. The reversal of 21318522 is 22581312.

It is an interprime number because it is at equal distance from previous prime (21318511) and next prime (21318533).

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

21318522 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21318492 and 21318501.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1776538 + ... + 1776549.

It is an arithmetic number, because the mean of its divisors is an integer number (5329632).

Almost surely, 2^21318522 is an apocalyptic number.

21318522 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21318522 is a wasteful number, since it uses less digits than its factorization.

21318522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3553092.

The product of its digits is 960, while the sum is 24.

The square root of 21318522 is about 4617.1985012559. The cubic root of 21318522 is about 277.2803098494.

Adding to 21318522 its reverse (22581312), we get a palindrome (43899834).

The spelling of 21318522 in words is "twenty-one million, three hundred eighteen thousand, five hundred twenty-two".