91270720 has 28 divisors (see below), whose sum is σ = 217339164. Its totient is φ = 36508160.

The previous prime is 91270667. The next prime is 91270747. The reversal of 91270720 is 2707219.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 49900096 + 41370624 = 7064^2 + 6432^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142291 + ... + 142930.

It is an arithmetic number, because the mean of its divisors is an integer number (7762113).

Almost surely, 2^91270720 is an apocalyptic number.

It is an amenable number.

91270720 is an abundant number, since it is smaller than the sum of its proper divisors (126068444).

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

91270720 is a wasteful number, since it uses less digits than its factorization.

91270720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285238 (or 285228 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 28.

The square root of 91270720 is about 9553.5710600801. The cubic root of 91270720 is about 450.2397405667.

Adding to 91270720 its reverse (2707219), we get a palindrome (93977939).

The spelling of 91270720 in words is "ninety-one million, two hundred seventy thousand, seven hundred twenty".