21218322 has 16 divisors (see below), whose sum is σ = 43805952. Its totient is φ = 6844560.

The previous prime is 21218321. The next prime is 21218333. The reversal of 21218322 is 22381212.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21218321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56853 + ... + 57224.

It is an arithmetic number, because the mean of its divisors is an integer number (2737872).

Almost surely, 2^21218322 is an apocalyptic number.

21218322 is an abundant number, since it is smaller than the sum of its proper divisors (22587630).

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

21218322 is a wasteful number, since it uses less digits than its factorization.

21218322 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114113.

The product of its digits is 384, while the sum is 21.

The square root of 21218322 is about 4606.3349856475. The cubic root of 21218322 is about 276.8452088637.

Adding to 21218322 its reverse (22381212), we get a palindrome (43599534).

The spelling of 21218322 in words is "twenty-one million, two hundred eighteen thousand, three hundred twenty-two".