91409 has 8 divisors (see below), whose sum is σ = 102240. Its totient is φ = 81216.

The previous prime is 91397. The next prime is 91411. The reversal of 91409 is 90419.

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 91409 - 2⁴ = 91393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 182 + ... + 464.

It is an arithmetic number, because the mean of its divisors is an integer number (12780).

2⁹¹⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

91409 is a deficient number, since it is larger than the sum of its proper divisors (10831).

91409 is a wasteful number, since it uses less digits than its factorization.

91409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 91409 is about 302.3392134673. The cubic root of 91409 is about 45.0467004892.

Subtracting from 91409 its reverse (90419), we obtain a triangular number (990 = T₄₄).

The spelling of 91409 in words is "ninety-one thousand, four hundred nine".