22201221 has 16 divisors (see below), whose sum is σ = 34745984. Its totient is φ = 12343104.

The previous prime is 22201217. The next prime is 22201237. The reversal of 22201221 is 12210222.

It is not a de Polignac number, because 22201221 - 2² = 22201217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 22201197 and 22201206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22201121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13510 + ... + 15063.

It is an arithmetic number, because the mean of its divisors is an integer number (2171624).

Almost surely, 2^22201221 is an apocalyptic number.

22201221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

22201221 is a deficient number, since it is larger than the sum of its proper divisors (12544763).

22201221 is a wasteful number, since it uses less digits than its factorization.

22201221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28620.

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

The square root of 22201221 is about 4711.8171653832. The cubic root of 22201221 is about 281.0556282686.

Adding to 22201221 its reverse (12210222), we get a palindrome (34411443).

Subtracting from 22201221 its reverse (12210222), we obtain a palindrome (9990999).

It can be divided in two parts, 22201 and 221, that added together give a palindrome (22422).

The spelling of 22201221 in words is "twenty-two million, two hundred one thousand, two hundred twenty-one".