28422221 has 2 divisors, whose sum is σ = 28422222. Its totient is φ = 28422220.

The previous prime is 28422217. The next prime is 28422259. The reversal of 28422221 is 12222482.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14546596 + 13875625 = 3814^2 + 3725^2 .

It is a cyclic number.

It is not a de Polignac number, because 28422221 - 2² = 28422217 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28422281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14211110 + 14211111.

It is an arithmetic number, because the mean of its divisors is an integer number (14211111).

Almost surely, 2^28422221 is an apocalyptic number.

It is an amenable number.

28422221 is a deficient number, since it is larger than the sum of its proper divisors (1).

28422221 is an equidigital number, since it uses as much as digits as its factorization.

28422221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1024, while the sum is 23.

The square root of 28422221 is about 5331.2494783118. The cubic root of 28422221 is about 305.1776122179.

The spelling of 28422221 in words is "twenty-eight million, four hundred twenty-two thousand, two hundred twenty-one".