640844484 has 48 divisors (see below), whose sum is σ = 1719838848. Its totient is φ = 181928448.

The previous prime is 640844471. The next prime is 640844549. The reversal of 640844484 is 484448046.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 11109 + ... + 37484.

It is an arithmetic number, because the mean of its divisors is an integer number (35829976).

Almost surely, 2^640844484 is an apocalyptic number.

It is an amenable number.

640844484 is an abundant number, since it is smaller than the sum of its proper divisors (1078994364).

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

640844484 is a wasteful number, since it uses less digits than its factorization.

640844484 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48764 (or 48762 counting only the distinct ones).

The product of its (nonzero) digits is 393216, while the sum is 42.

The square root of 640844484 is about 25314.9063596925. The cubic root of 640844484 is about 862.1527480921.

The spelling of 640844484 in words is "six hundred forty million, eight hundred forty-four thousand, four hundred eighty-four".