221022209 has 2 divisors, whose sum is σ = 221022210. Its totient is φ = 221022208.

The previous prime is 221022199. The next prime is 221022211. The reversal of 221022209 is 902220122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 132135025 + 88887184 = 11495^2 + 9428^2 .

It is a cyclic number.

It is not a de Polignac number, because 221022209 - 2¹² = 221018113 is a prime.

Together with 221022211, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (221022229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110511104 + 110511105.

It is an arithmetic number, because the mean of its divisors is an integer number (110511105).

Almost surely, 2^221022209 is an apocalyptic number.

It is an amenable number.

221022209 is a deficient number, since it is larger than the sum of its proper divisors (1).

221022209 is an equidigital number, since it uses as much as digits as its factorization.

221022209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 221022209 is about 14866.8156980572. The cubic root of 221022209 is about 604.6146114661.

The spelling of 221022209 in words is "two hundred twenty-one million, twenty-two thousand, two hundred nine".