91761280 has 128 divisors (see below), whose sum is σ = 242902800. Its totient is φ = 32931840.

The previous prime is 91761277. The next prime is 91761287. The reversal of 91761280 is 8216719.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 61504 + 91699776 = 248^2 + 9576^2 .

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (91761287) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 340986 + ... + 341254.

Almost surely, 2^91761280 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 91761280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121451400).

91761280 is an abundant number, since it is smaller than the sum of its proper divisors (151141520).

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

91761280 is a wasteful number, since it uses less digits than its factorization.

91761280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342 (or 330 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 91761280 is about 9579.2108234447. The cubic root of 91761280 is about 451.0449461354.

Adding to 91761280 its reverse (8216719), we get a palindrome (99977999).

The spelling of 91761280 in words is "ninety-one million, seven hundred sixty-one thousand, two hundred eighty".