91388 has 24 divisors (see below), whose sum is σ = 182784. Its totient is φ = 39600.

The previous prime is 91387. The next prime is 91393. The reversal of 91388 is 88319.

It is a happy number.

91388 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 91388.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 91388.

It is not an unprimeable number, because it can be changed into a prime (91381) 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, 1331 + ... + 1397.

It is an arithmetic number, because the mean of its divisors is an integer number (7616).

2⁹¹³⁸⁸ is an apocalyptic number.

It is an amenable number.

91388 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a weird number, because it is abundant, but not a pseudoperfect number.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91392).

91388 is a wasteful number, since it uses less digits than its factorization.

91388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 111 counting only the distinct ones).

The product of its digits is 1728, while the sum is 29.

The square root of 91388 is about 302.3044822691. The cubic root of 91388 is about 45.0432505985.

It can be divided in two parts, 913 and 88, that added together give a palindrome (1001).

The spelling of 91388 in words is "ninety-one thousand, three hundred eighty-eight".