8991040 has 28 divisors (see below), whose sum is σ = 21410676. Its totient is φ = 3596288.

The previous prime is 8991029. The next prime is 8991041. The reversal of 8991040 is 401998.

It can be written as a sum of positive squares in 2 ways, for example, as 1016064 + 7974976 = 1008^2 + 2824^2 .

It is a junction number, because it is equal to n+sod(n) for n = 8990993 and 8991011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8991041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13729 + ... + 14368.

It is an arithmetic number, because the mean of its divisors is an integer number (764667).

Almost surely, 2^8991040 is an apocalyptic number.

8991040 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8991040 is an abundant number, since it is smaller than the sum of its proper divisors (12419636).

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

8991040 is a wasteful number, since it uses less digits than its factorization.

8991040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28114 (or 28104 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 8991040 is about 2998.5062948075. The cubic root of 8991040 is about 207.9393314186.

The spelling of 8991040 in words is "eight million, nine hundred ninety-one thousand, forty".