640389484 has 96 divisors (see below), whose sum is σ = 1370880000. Its totient is φ = 255999744.

The previous prime is 640389479. The next prime is 640389511. The reversal of 640389484 is 484983046.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4297842 + ... + 4297990.

It is an arithmetic number, because the mean of its divisors is an integer number (14280000).

Almost surely, 2^640389484 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 640389484, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (685440000).

640389484 is an abundant number, since it is smaller than the sum of its proper divisors (730490516).

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

640389484 is a wasteful number, since it uses less digits than its factorization.

640389484 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335 (or 333 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 46.

The square root of 640389484 is about 25305.9179639862. The cubic root of 640389484 is about 861.9486567790.

The spelling of 640389484 in words is "six hundred forty million, three hundred eighty-nine thousand, four hundred eighty-four".