91013280 has 96 divisors (see below), whose sum is σ = 289142784. Its totient is φ = 24062976.

The previous prime is 91013239. The next prime is 91013311. The reversal of 91013280 is 8231019.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 91013280.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60214 + ... + 61706.

It is an arithmetic number, because the mean of its divisors is an integer number (3011904).

Almost surely, 2^91013280 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 91013280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144571392).

91013280 is an abundant number, since it is smaller than the sum of its proper divisors (198129504).

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

91013280 is a wasteful number, since it uses less digits than its factorization.

91013280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1638 (or 1630 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 91013280 is about 9540.0880499081. The cubic root of 91013280 is about 449.8160235594.

Adding to 91013280 its reverse (8231019), we get a palindrome (99244299).

The spelling of 91013280 in words is "ninety-one million, thirteen thousand, two hundred eighty".