91965221 has 2 divisors, whose sum is σ = 91965222. Its totient is φ = 91965220.

The previous prime is 91965179. The next prime is 91965241. The reversal of 91965221 is 12256919.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56085121 + 35880100 = 7489^2 + 5990^2 .

It is a cyclic number.

It is not a de Polignac number, because 91965221 - 2¹⁸ = 91703077 is a prime.

It is a super-3 number, since 3×91965221³ (a number of 25 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91965241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45982610 + 45982611.

It is an arithmetic number, because the mean of its divisors is an integer number (45982611).

Almost surely, 2^91965221 is an apocalyptic number.

It is an amenable number.

91965221 is a deficient number, since it is larger than the sum of its proper divisors (1).

91965221 is an equidigital number, since it uses as much as digits as its factorization.

91965221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9720, while the sum is 35.

The square root of 91965221 is about 9589.8498945500. The cubic root of 91965221 is about 451.3788505671.

The spelling of 91965221 in words is "ninety-one million, nine hundred sixty-five thousand, two hundred twenty-one".