991080 has 48 divisors (see below), whose sum is σ = 3222180. Its totient is φ = 264192.

The previous prime is 991079. The next prime is 991091. The reversal of 991080 is 80199.

It can be written as a sum of positive squares in 2 ways, for example, as 956484 + 34596 = 978^2 + 186^2 .

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 991080.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1017 + ... + 1736.

2⁹⁹¹⁰⁸⁰ is an apocalyptic number.

991080 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

991080 is an abundant number, since it is smaller than the sum of its proper divisors (2231100).

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

991080 is a wasteful number, since it uses less digits than its factorization.

991080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2770 (or 2763 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 991080 is about 995.5300095929. The cubic root of 991080 is about 99.7017781883.

The spelling of 991080 in words is "nine hundred ninety-one thousand, eighty".