91622581 has 2 divisors, whose sum is σ = 91622582. Its totient is φ = 91622580.

The previous prime is 91622561. The next prime is 91622603. The reversal of 91622581 is 18522619.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87721956 + 3900625 = 9366^2 + 1975^2 .

It is a cyclic number.

It is not a de Polignac number, because 91622581 - 2²⁵ = 58068149 is a prime.

It is a super-2 number, since 2×91622581² = 16789394698203122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91622521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45811290 + 45811291.

It is an arithmetic number, because the mean of its divisors is an integer number (45811291).

Almost surely, 2^91622581 is an apocalyptic number.

It is an amenable number.

91622581 is a deficient number, since it is larger than the sum of its proper divisors (1).

91622581 is an equidigital number, since it uses as much as digits as its factorization.

91622581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 34.

The square root of 91622581 is about 9571.9685018287. The cubic root of 91622581 is about 450.8175770699.

The spelling of 91622581 in words is "ninety-one million, six hundred twenty-two thousand, five hundred eighty-one".