91839 has 16 divisors (see below), whose sum is σ = 140544. Its totient is φ = 53240.

The previous prime is 91837. The next prime is 91841. The reversal of 91839 is 93819.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (91837) and next prime (91841).

It is not a de Polignac number, because 91839 - 2¹ = 91837 is a prime.

It is a plaindrome in base 14 and base 16.

It is a nialpdrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91837) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3982 + ... + 4004.

It is an arithmetic number, because the mean of its divisors is an integer number (8784).

2⁹¹⁸³⁹ is an apocalyptic number.

91839 is a deficient number, since it is larger than the sum of its proper divisors (48705).

91839 is a wasteful number, since it uses less digits than its factorization.

91839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59 (or 37 counting only the distinct ones).

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

The square root of 91839 is about 303.0495009070. The cubic root of 91839 is about 45.1172252267.

Subtracting from 91839 its sum of digits (30), we obtain a square (91809 = 303²).

The spelling of 91839 in words is "ninety-one thousand, eight hundred thirty-nine".