91091023 has 2 divisors, whose sum is σ = 91091024. Its totient is φ = 91091022.

The previous prime is 91090957. The next prime is 91091041. The reversal of 91091023 is 32019019.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91091023 - 2²¹ = 88993871 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91091723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45545511 + 45545512.

It is an arithmetic number, because the mean of its divisors is an integer number (45545512).

Almost surely, 2^91091023 is an apocalyptic number.

91091023 is a deficient number, since it is larger than the sum of its proper divisors (1).

91091023 is an equidigital number, since it uses as much as digits as its factorization.

91091023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 91091023 is about 9544.1617232736. The cubic root of 91091023 is about 449.9440638292.

The spelling of 91091023 in words is "ninety-one million, ninety-one thousand, twenty-three".