22021212 has 36 divisors (see below), whose sum is σ = 53729480. Its totient is φ = 7019232.

The previous prime is 22021211. The next prime is 22021229. The reversal of 22021212 is 21212022.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22021211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4614 + ... + 8082.

Almost surely, 2^22021212 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 22021212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26864740).

22021212 is an abundant number, since it is smaller than the sum of its proper divisors (31708268).

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

22021212 is a wasteful number, since it uses less digits than its factorization.

22021212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3522 (or 3497 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 22021212 is about 4692.6764218301. The cubic root of 22021212 is about 280.2939599835.

Adding to 22021212 its reverse (21212022), we get a palindrome (43233234).

The spelling of 22021212 in words is "twenty-two million, twenty-one thousand, two hundred twelve".