91005 has 8 divisors (see below), whose sum is σ = 145632. Its totient is φ = 48528.

The previous prime is 90997. The next prime is 91009. The reversal of 91005 is 50019.

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

It is not a de Polignac number, because 91005 - 2³ = 90997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15), and also a Moran number because the ratio is a prime number: 6067 = 91005 / (9 + 1 + 0 + 0 + 5).

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91009) 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 7 ways as a sum of consecutive naturals, for example, 3019 + ... + 3048.

It is an arithmetic number, because the mean of its divisors is an integer number (18204).

2⁹¹⁰⁰⁵ is an apocalyptic number.

It is an amenable number.

91005 is a deficient number, since it is larger than the sum of its proper divisors (54627).

91005 is a wasteful number, since it uses less digits than its factorization.

91005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6075.

The product of its (nonzero) digits is 45, while the sum is 15.

The square root of 91005 is about 301.6703498854. The cubic root of 91005 is about 44.9802382365.

It can be divided in two parts, 9 and 1005, that multiplied together give a triangular number (9045 = T₁₃₄).

The spelling of 91005 in words is "ninety-one thousand, five".