8640440 has 32 divisors (see below), whose sum is σ = 20466000. Its totient is φ = 3273984.

The previous prime is 8640439. The next prime is 8640451. The reversal of 8640440 is 440468.

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 7 ways as a sum of consecutive naturals, for example, 4925 + ... + 6444.

Almost surely, 2^8640440 is an apocalyptic number.

It is an amenable number.

8640440 is an abundant number, since it is smaller than the sum of its proper divisors (11825560).

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

8640440 is a wasteful number, since it uses less digits than its factorization.

8640440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11399 (or 11395 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 26.

The square root of 8640440 is about 2939.4625359069. The cubic root of 8640440 is about 205.2005968264.

Subtracting from 8640440 its product of nonzero digits (3072), we obtain a palindrome (8637368).

The spelling of 8640440 in words is "eight million, six hundred forty thousand, four hundred forty".