91540 has 24 divisors (see below), whose sum is σ = 201600. Its totient is φ = 34848.

The previous prime is 91529. The next prime is 91541. The reversal of 91540 is 4519.

91540 = 71² + 72² + ... + 85².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91541) 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, 361 + ... + 559.

It is an arithmetic number, because the mean of its divisors is an integer number (8400).

2⁹¹⁵⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100800).

91540 is an abundant number, since it is smaller than the sum of its proper divisors (110060).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91540 is a wasteful number, since it uses less digits than its factorization.

91540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231 (or 229 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 91540 is about 302.5557799811. Note that the first 3 decimals coincide. The cubic root of 91540 is about 45.0682093158.

The spelling of 91540 in words is "ninety-one thousand, five hundred forty".