91140720 has 320 divisors, whose sum is σ = 342835200. Its totient is φ = 19768320.

The previous prime is 91140667. The next prime is 91140733. The reversal of 91140720 is 2704119.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1153641 + ... + 1153719.

It is an arithmetic number, because the mean of its divisors is an integer number (1071360).

Almost surely, 2^91140720 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 91140720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171417600).

91140720 is an abundant number, since it is smaller than the sum of its proper divisors (251694480).

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

91140720 is a wasteful number, since it uses less digits than its factorization.

91140720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148 (or 142 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 91140720 is about 9546.7648970738. The cubic root of 91140720 is about 450.0258750554.

Adding to 91140720 its reverse (2704119), we get a palindrome (93844839).

The spelling of 91140720 in words is "ninety-one million, one hundred forty thousand, seven hundred twenty".