91083240 has 72 divisors (see below), whose sum is σ = 296610210. Its totient is φ = 24240576.

The previous prime is 91083221. The next prime is 91083241. The reversal of 91083240 is 4238019.

It can be written as a sum of positive squares in only one way, i.e., 81974916 + 9108324 = 9054^2 + 3018^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is not an unprimeable number, because it can be changed into a prime (91083241) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 180829 + ... + 181331.

Almost surely, 2^91083240 is an apocalyptic number.

91083240 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91083240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148305105).

91083240 is an abundant number, since it is smaller than the sum of its proper divisors (205526970).

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

91083240 is a wasteful number, since it uses less digits than its factorization.

91083240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1023 (or 513 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 91083240 is about 9543.7539783882. The cubic root of 91083240 is about 449.9312487559.

The spelling of 91083240 in words is "ninety-one million, eighty-three thousand, two hundred forty".