91581760 has 56 divisors (see below), whose sum is σ = 219776040. Its totient is φ = 36347904.

The previous prime is 91581757. The next prime is 91581761. The reversal of 91581760 is 6718519.

It can be written as a sum of positive squares in 4 ways, for example, as 27709696 + 63872064 = 5264^2 + 7992^2 .

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91581761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42796 + ... + 44884.

Almost surely, 2^91581760 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 91581760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109888020).

91581760 is an abundant number, since it is smaller than the sum of its proper divisors (128194280).

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

91581760 is a wasteful number, since it uses less digits than its factorization.

91581760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2243 (or 2233 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 37.

The square root of 91581760 is about 9569.8359442574. The cubic root of 91581760 is about 450.7506155639.

The spelling of 91581760 in words is "ninety-one million, five hundred eighty-one thousand, seven hundred sixty".