22388221 has 2 divisors, whose sum is σ = 22388222. Its totient is φ = 22388220.

The previous prime is 22388189. The next prime is 22388227. The reversal of 22388221 is 12288322.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16088121 + 6300100 = 4011^2 + 2510^2 .

It is a cyclic number.

It is not a de Polignac number, because 22388221 - 2⁵ = 22388189 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 22388221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22388227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11194110 + 11194111.

It is an arithmetic number, because the mean of its divisors is an integer number (11194111).

Almost surely, 2^22388221 is an apocalyptic number.

It is an amenable number.

22388221 is a deficient number, since it is larger than the sum of its proper divisors (1).

22388221 is an equidigital number, since it uses as much as digits as its factorization.

22388221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3072, while the sum is 28.

The square root of 22388221 is about 4731.6192788516. The cubic root of 22388221 is about 281.8425298265.

The spelling of 22388221 in words is "twenty-two million, three hundred eighty-eight thousand, two hundred twenty-one".