22170221 has 2 divisors, whose sum is σ = 22170222. Its totient is φ = 22170220.

The previous prime is 22170199. The next prime is 22170331. The reversal of 22170221 is 12207122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17547721 + 4622500 = 4189^2 + 2150^2 .

It is a cyclic number.

It is not a de Polignac number, because 22170221 - 2¹⁴ = 22153837 is a prime.

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 22170221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22170121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11085110 + 11085111.

It is an arithmetic number, because the mean of its divisors is an integer number (11085111).

Almost surely, 2^22170221 is an apocalyptic number.

It is an amenable number.

22170221 is a deficient number, since it is larger than the sum of its proper divisors (1).

22170221 is an equidigital number, since it uses as much as digits as its factorization.

22170221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 22170221 is about 4708.5264149201. The cubic root of 22170221 is about 280.9247528410.

Adding to 22170221 its reverse (12207122), we get a palindrome (34377343).

The spelling of 22170221 in words is "twenty-two million, one hundred seventy thousand, two hundred twenty-one".