91229557 has 2 divisors, whose sum is σ = 91229558. Its totient is φ = 91229556.

The previous prime is 91229549. The next prime is 91229609. The reversal of 91229557 is 75592219.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90801841 + 427716 = 9529^2 + 654^2 .

It is a cyclic number.

It is not a de Polignac number, because 91229557 - 2³ = 91229549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91229527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45614778 + 45614779.

It is an arithmetic number, because the mean of its divisors is an integer number (45614779).

Almost surely, 2^91229557 is an apocalyptic number.

It is an amenable number.

91229557 is a deficient number, since it is larger than the sum of its proper divisors (1).

91229557 is an equidigital number, since it uses as much as digits as its factorization.

91229557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56700, while the sum is 40.

The square root of 91229557 is about 9551.4164918090. The cubic root of 91229557 is about 450.1720445034.

The spelling of 91229557 in words is "ninety-one million, two hundred twenty-nine thousand, five hundred fifty-seven".