91530991 has 2 divisors, whose sum is σ = 91530992. Its totient is φ = 91530990.

The previous prime is 91530953. The next prime is 91530997. The reversal of 91530991 is 19903519.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91530991 - 2¹³ = 91522799 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91530991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91530997) 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, 45765495 + 45765496.

It is an arithmetic number, because the mean of its divisors is an integer number (45765496).

Almost surely, 2^91530991 is an apocalyptic number.

91530991 is a deficient number, since it is larger than the sum of its proper divisors (1).

91530991 is an equidigital number, since it uses as much as digits as its factorization.

91530991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10935, while the sum is 37.

The square root of 91530991 is about 9567.1830232310. The cubic root of 91530991 is about 450.6673078981.

The spelling of 91530991 in words is "ninety-one million, five hundred thirty thousand, nine hundred ninety-one".