640444060 has 24 divisors (see below), whose sum is σ = 1424046960. Its totient is φ = 241108224.

The previous prime is 640444037. The next prime is 640444061. The reversal of 640444060 is 60444046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640444061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 941490 + ... + 942169.

It is an arithmetic number, because the mean of its divisors is an integer number (59335290).

Almost surely, 2^640444060 is an apocalyptic number.

It is an amenable number.

640444060 is an abundant number, since it is smaller than the sum of its proper divisors (783602900).

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

640444060 is a wasteful number, since it uses less digits than its factorization.

640444060 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1883685 (or 1883683 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

The square root of 640444060 is about 25306.9962658550. The cubic root of 640444060 is about 861.9731420726.

The spelling of 640444060 in words is "six hundred forty million, four hundred forty-four thousand, sixty".