91091289 has 8 divisors (see below), whose sum is σ = 121521600. Its totient is φ = 60694256.

The previous prime is 91091281. The next prime is 91091303. The reversal of 91091289 is 98219019.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91091289 - 2³ = 91091281 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (91091281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1014 + ... + 13535.

It is an arithmetic number, because the mean of its divisors is an integer number (15190200).

Almost surely, 2^91091289 is an apocalyptic number.

It is an amenable number.

91091289 is a deficient number, since it is larger than the sum of its proper divisors (30430311).

91091289 is a wasteful number, since it uses less digits than its factorization.

91091289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16639.

The product of its (nonzero) digits is 11664, while the sum is 39.

The square root of 91091289 is about 9544.1756584841. The cubic root of 91091289 is about 449.9445017977.

The spelling of 91091289 in words is "ninety-one million, ninety-one thousand, two hundred eighty-nine".