8640040 has 32 divisors (see below), whose sum is σ = 19764360. Its totient is φ = 3398400.

The previous prime is 8640017. The next prime is 8640059. The reversal of 8640040 is 400468.

It can be written as a sum of positive squares in 4 ways, for example, as 4137156 + 4502884 = 2034^2 + 2122^2 .

It is a junction number, because it is equal to n+sod(n) for n = 8639993 and 8640020.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 670 + ... + 4210.

Almost surely, 2^8640040 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 8640040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9882180).

8640040 is an abundant number, since it is smaller than the sum of its proper divisors (11124320).

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

8640040 is a wasteful number, since it uses less digits than its factorization.

8640040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3613 (or 3609 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 8640040 is about 2939.3944954701. The cubic root of 8640040 is about 205.1974302629.

The spelling of 8640040 in words is "eight million, six hundred forty thousand, forty".