221939161 has 2 divisors, whose sum is σ = 221939162. Its totient is φ = 221939160.

The previous prime is 221939149. The next prime is 221939177. The reversal of 221939161 is 161939122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 203233536 + 18705625 = 14256^2 + 4325^2 .

It is a cyclic number.

It is not a de Polignac number, because 221939161 - 2¹¹ = 221937113 is a prime.

It is not a weakly prime, because it can be changed into another prime (221939111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110969580 + 110969581.

It is an arithmetic number, because the mean of its divisors is an integer number (110969581).

Almost surely, 2^221939161 is an apocalyptic number.

It is an amenable number.

221939161 is a deficient number, since it is larger than the sum of its proper divisors (1).

221939161 is an equidigital number, since it uses as much as digits as its factorization.

221939161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5832, while the sum is 34.

The square root of 221939161 is about 14897.6226626935. The cubic root of 221939161 is about 605.4495768163.

The spelling of 221939161 in words is "two hundred twenty-one million, nine hundred thirty-nine thousand, one hundred sixty-one".