91983 has 4 divisors (see below), whose sum is σ = 122648. Its totient is φ = 61320.

The previous prime is 91969. The next prime is 91997. The reversal of 91983 is 38919.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 38919 = 3 ⋅12973.

It is an interprime number because it is at equal distance from previous prime (91969) and next prime (91997).

It is not a de Polignac number, because 91983 - 2⁴ = 91967 is a prime.

It is a D-number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91983.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91943) 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, 15328 + ... + 15333.

It is an arithmetic number, because the mean of its divisors is an integer number (30662).

2⁹¹⁹⁸³ is an apocalyptic number.

91983 is a deficient number, since it is larger than the sum of its proper divisors (30665).

91983 is a wasteful number, since it uses less digits than its factorization.

91983 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30664.

The product of its digits is 1944, while the sum is 30.

The square root of 91983 is about 303.2869927973. The cubic root of 91983 is about 45.1407936010.

The spelling of 91983 in words is "ninety-one thousand, nine hundred eighty-three".