91581120 has 84 divisors (see below), whose sum is σ = 315010800. Its totient is φ = 24420864.

The previous prime is 91581067. The next prime is 91581131. The reversal of 91581120 is 2118519.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 13020 + ... + 18779.

Almost surely, 2^91581120 is an apocalyptic number.

91581120 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

91581120 is an abundant number, since it is smaller than the sum of its proper divisors (223429680).

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

91581120 is a wasteful number, since it uses less digits than its factorization.

91581120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31822 (or 31809 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 91581120 is about 9569.8025057992. The cubic root of 91581120 is about 450.7495655693.

Adding to 91581120 its reverse (2118519), we get a palindrome (93699639).

The spelling of 91581120 in words is "ninety-one million, five hundred eighty-one thousand, one hundred twenty".