640288404 has 144 divisors (see below), whose sum is σ = 1945111168. Its totient is φ = 173746944.

The previous prime is 640288403. The next prime is 640288417. The reversal of 640288404 is 404882046.

640288404 is a `hidden beast` number, since 640 + 2 + 8 + 8 + 4 + 0 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640288403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 400134 + ... + 401730.

Almost surely, 2^640288404 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 640288404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (972555584).

640288404 is an abundant number, since it is smaller than the sum of its proper divisors (1304822764).

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

640288404 is a wasteful number, since it uses less digits than its factorization.

640288404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1694 (or 1689 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 36.

The square root of 640288404 is about 25303.9207238720. The cubic root of 640288404 is about 861.9033039863.

The spelling of 640288404 in words is "six hundred forty million, two hundred eighty-eight thousand, four hundred four".