8991090 has 24 divisors (see below), whose sum is σ = 23377068. Its totient is φ = 2397600.

The previous prime is 8991089. The next prime is 8991097. The reversal of 8991090 is 901998.

It can be written as a sum of positive squares in 2 ways, for example, as 8485569 + 505521 = 2913^2 + 711^2 .

It is not an unprimeable number, because it can be changed into a prime (8991097) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 49861 + ... + 50040.

Almost surely, 2^8991090 is an apocalyptic number.

8991090 is an abundant number, since it is smaller than the sum of its proper divisors (14385978).

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

8991090 is a wasteful number, since it uses less digits than its factorization.

8991090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99914 (or 99911 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 36.

The square root of 8991090 is about 2998.5146322805. The cubic root of 8991090 is about 207.9397168744.

It can be divided in two parts, 89910 and 90, that added together give a square (90000 = 300²).

The spelling of 8991090 in words is "eight million, nine hundred ninety-one thousand, ninety".