21222312 has 32 divisors (see below), whose sum is σ = 54492000. Its totient is φ = 6882624.

The previous prime is 21222293. The next prime is 21222343. The reversal of 21222312 is 21322212.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21222291 and 21222300.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11062 + ... + 12837.

It is an arithmetic number, because the mean of its divisors is an integer number (1702875).

Almost surely, 2^21222312 is an apocalyptic number.

It is an amenable number.

21222312 is an abundant number, since it is smaller than the sum of its proper divisors (33269688).

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

21222312 is a wasteful number, since it uses less digits than its factorization.

21222312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23945 (or 23941 counting only the distinct ones).

The product of its digits is 96, while the sum is 15.

The square root of 21222312 is about 4606.7680644895. The cubic root of 21222312 is about 276.8625608979.

Adding to 21222312 its reverse (21322212), we get a palindrome (42544524).

The spelling of 21222312 in words is "twenty-one million, two hundred twenty-two thousand, three hundred twelve".