16922221 has 2 divisors, whose sum is σ = 16922222. Its totient is φ = 16922220.

The previous prime is 16922201. The next prime is 16922237. The reversal of 16922221 is 12222961.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13060996 + 3861225 = 3614^2 + 1965^2 .

It is a cyclic number.

It is not a de Polignac number, because 16922221 - 2⁵ = 16922189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16922201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8461110 + 8461111.

It is an arithmetic number, because the mean of its divisors is an integer number (8461111).

Almost surely, 2^16922221 is an apocalyptic number.

It is an amenable number.

16922221 is a deficient number, since it is larger than the sum of its proper divisors (1).

16922221 is an equidigital number, since it uses as much as digits as its factorization.

16922221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 25.

The square root of 16922221 is about 4113.6627231702. The cubic root of 16922221 is about 256.7354188864.

The spelling of 16922221 in words is "sixteen million, nine hundred twenty-two thousand, two hundred twenty-one".