22611221 has 2 divisors, whose sum is σ = 22611222. Its totient is φ = 22611220.

The previous prime is 22611209. The next prime is 22611223. The reversal of 22611221 is 12211622.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20376196 + 2235025 = 4514^2 + 1495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22611221 is a prime.

It is a super-2 number, since 2×22611221² = 1022534630221682, which contains 22 as substring.

Together with 22611223, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 22611221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22611223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11305610 + 11305611.

It is an arithmetic number, because the mean of its divisors is an integer number (11305611).

Almost surely, 2^22611221 is an apocalyptic number.

It is an amenable number.

22611221 is a deficient number, since it is larger than the sum of its proper divisors (1).

22611221 is an equidigital number, since it uses as much as digits as its factorization.

22611221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96, while the sum is 17.

The square root of 22611221 is about 4755.1257606923. The cubic root of 22611221 is about 282.7752130425.

Adding to 22611221 its reverse (12211622), we get a palindrome (34822843).

The spelling of 22611221 in words is "twenty-two million, six hundred eleven thousand, two hundred twenty-one".