640189704 has 192 divisors, whose sum is σ = 2052820800. Its totient is φ = 165876480.

The previous prime is 640189699. The next prime is 640189769. The reversal of 640189704 is 407981046.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1565052 + ... + 1565460.

It is an arithmetic number, because the mean of its divisors is an integer number (10691775).

Almost surely, 2^640189704 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 640189704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1026410400).

640189704 is an abundant number, since it is smaller than the sum of its proper divisors (1412631096).

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

640189704 is a wasteful number, since it uses less digits than its factorization.

640189704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465 (or 432 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 640189704 is about 25301.9703580571. The cubic root of 640189704 is about 861.8590144509.

The spelling of 640189704 in words is "six hundred forty million, one hundred eighty-nine thousand, seven hundred four".