91909291 has 2 divisors, whose sum is σ = 91909292. Its totient is φ = 91909290.

The previous prime is 91909267. The next prime is 91909319. The reversal of 91909291 is 19290919.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91909291 - 2¹⁵ = 91876523 is a prime.

It is not a weakly prime, because it can be changed into another prime (91909231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45954645 + 45954646.

It is an arithmetic number, because the mean of its divisors is an integer number (45954646).

Almost surely, 2^91909291 is an apocalyptic number.

91909291 is a deficient number, since it is larger than the sum of its proper divisors (1).

91909291 is an equidigital number, since it uses as much as digits as its factorization.

91909291 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13122, while the sum is 40.

The square root of 91909291 is about 9586.9333470094. The cubic root of 91909291 is about 451.2873277849.

It can be divided in two parts, 9190 and 9291, that added together give a palindrome (18481).

The spelling of 91909291 in words is "ninety-one million, nine hundred nine thousand, two hundred ninety-one".