22288221 has 6 divisors (see below), whose sum is σ = 32194110. Its totient is φ = 14858808.

The previous prime is 22288213. The next prime is 22288223. The reversal of 22288221 is 12288222.

It can be written as a sum of positive squares in only one way, i.e., 16088121 + 6200100 = 4011^2 + 2490^2 .

It is not a de Polignac number, because 22288221 - 2³ = 22288213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22288223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1238226 + ... + 1238243.

It is an arithmetic number, because the mean of its divisors is an integer number (5365685).

Almost surely, 2^22288221 is an apocalyptic number.

It is an amenable number.

22288221 is a deficient number, since it is larger than the sum of its proper divisors (9905889).

22288221 is a wasteful number, since it uses less digits than its factorization.

22288221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2476475 (or 2476472 counting only the distinct ones).

The product of its digits is 2048, while the sum is 27.

The square root of 22288221 is about 4721.0402455391. The cubic root of 22288221 is about 281.4222743070.

Subtracting from 22288221 its reverse (12288222), we obtain a palindrome (9999999).

The spelling of 22288221 in words is "twenty-two million, two hundred eighty-eight thousand, two hundred twenty-one".