221220289 has 2 divisors, whose sum is σ = 221220290. Its totient is φ = 221220288.

The previous prime is 221220283. The next prime is 221220301. The reversal of 221220289 is 982022122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 220819600 + 400689 = 14860^2 + 633^2 .

It is a cyclic number.

It is not a de Polignac number, because 221220289 - 2⁵ = 221220257 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (221220283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110610144 + 110610145.

It is an arithmetic number, because the mean of its divisors is an integer number (110610145).

Almost surely, 2^221220289 is an apocalyptic number.

It is an amenable number.

221220289 is a deficient number, since it is larger than the sum of its proper divisors (1).

221220289 is an equidigital number, since it uses as much as digits as its factorization.

221220289 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 221220289 is about 14873.4760227729. The cubic root of 221220289 is about 604.7951759799.

The spelling of 221220289 in words is "two hundred twenty-one million, two hundred twenty thousand, two hundred eighty-nine".