22021221 has 8 divisors (see below), whose sum is σ = 29485440. Its totient is φ = 14618912.

The previous prime is 22021211. The next prime is 22021229. The reversal of 22021221 is 12212022.

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

It is a cyclic number.

It is not a de Polignac number, because 22021221 - 2⁷ = 22021093 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 22021197 and 22021206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22021229) 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, 14640 + ... + 16073.

It is an arithmetic number, because the mean of its divisors is an integer number (3685680).

Almost surely, 2^22021221 is an apocalyptic number.

It is an amenable number.

22021221 is a deficient number, since it is larger than the sum of its proper divisors (7464219).

22021221 is a wasteful number, since it uses less digits than its factorization.

22021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30955.

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

The square root of 22021221 is about 4692.6773807710. The cubic root of 22021221 is about 280.2939981686.

Adding to 22021221 its reverse (12212022), we get a palindrome (34233243).

The spelling of 22021221 in words is "twenty-two million, twenty-one thousand, two hundred twenty-one".