91087 has 4 divisors (see below), whose sum is σ = 92320. Its totient is φ = 89856.

The previous prime is 91081. The next prime is 91097. The reversal of 91087 is 78019.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78019 = 61 ⋅1279.

It is a cyclic number.

It is not a de Polignac number, because 91087 - 2³ = 91079 is a prime.

It is a Duffinian number.

91087 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 91087.

It is not an unprimeable number, because it can be changed into a prime (91081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 498 + ... + 655.

It is an arithmetic number, because the mean of its divisors is an integer number (23080).

2⁹¹⁰⁸⁷ is an apocalyptic number.

91087 is a deficient number, since it is larger than the sum of its proper divisors (1233).

91087 is a wasteful number, since it uses less digits than its factorization.

91087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1232.

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 91087 is about 301.8062292266. The cubic root of 91087 is about 44.9937439863.

The spelling of 91087 in words is "ninety-one thousand, eighty-seven".