91129091 has 4 divisors (see below), whose sum is σ = 91245672. Its totient is φ = 91012512.

The previous prime is 91129081. The next prime is 91129117. The reversal of 91129091 is 19092119.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19092119 = 67 ⋅284957.

It is a cyclic number.

It is not a de Polignac number, because 91129091 - 2¹⁰ = 91128067 is a prime.

It is a super-2 number, since 2×91129091² = 16609022452972562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91129021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57110 + ... + 58683.

It is an arithmetic number, because the mean of its divisors is an integer number (22811418).

Almost surely, 2^91129091 is an apocalyptic number.

91129091 is a deficient number, since it is larger than the sum of its proper divisors (116581).

91129091 is a wasteful number, since it uses less digits than its factorization.

91129091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116580.

The product of its (nonzero) digits is 1458, while the sum is 32.

The square root of 91129091 is about 9546.1558231573. The cubic root of 91129091 is about 450.0067340556.

The spelling of 91129091 in words is "ninety-one million, one hundred twenty-nine thousand, ninety-one".