221965169 has 2 divisors, whose sum is σ = 221965170. Its totient is φ = 221965168.

The previous prime is 221965123. The next prime is 221965181. The reversal of 221965169 is 961569122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 177875569 + 44089600 = 13337^2 + 6640^2 .

It is a cyclic number.

It is not a de Polignac number, because 221965169 - 2¹² = 221961073 is a prime.

It is a super-2 number, since 2×221965169² = 98537072498397122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (221965769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110982584 + 110982585.

It is an arithmetic number, because the mean of its divisors is an integer number (110982585).

Almost surely, 2^221965169 is an apocalyptic number.

It is an amenable number.

221965169 is a deficient number, since it is larger than the sum of its proper divisors (1).

221965169 is an equidigital number, since it uses as much as digits as its factorization.

221965169 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58320, while the sum is 41.

The square root of 221965169 is about 14898.4955280726. The cubic root of 221965169 is about 605.4732258162.

The spelling of 221965169 in words is "two hundred twenty-one million, nine hundred sixty-five thousand, one hundred sixty-nine".