91399 has 8 divisors (see below), whose sum is σ = 114048. Its totient is φ = 71160.

The previous prime is 91397. The next prime is 91411. The reversal of 91399 is 99319.

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 91399 - 2¹ = 91397 is a prime.

91399 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 91399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91393) 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, 517 + ... + 670.

It is an arithmetic number, because the mean of its divisors is an integer number (14256).

2⁹¹³⁹⁹ is an apocalyptic number.

91399 is a deficient number, since it is larger than the sum of its proper divisors (22649).

91399 is a wasteful number, since it uses less digits than its factorization.

91399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1205.

The product of its digits is 2187, while the sum is 31.

The square root of 91399 is about 302.3226752991. The cubic root of 91399 is about 45.0450577500.

The spelling of 91399 in words is "ninety-one thousand, three hundred ninety-nine".