640555060 has 48 divisors (see below), whose sum is σ = 1408046976. Its totient is φ = 244314752.

The previous prime is 640555031. The next prime is 640555061. The reversal of 640555060 is 60555046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640555061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 157614 + ... + 161626.

It is an arithmetic number, because the mean of its divisors is an integer number (29334312).

Almost surely, 2^640555060 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 640555060, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (704023488).

640555060 is an abundant number, since it is smaller than the sum of its proper divisors (767491916).

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

640555060 is a wasteful number, since it uses less digits than its factorization.

640555060 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4392 (or 4390 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 31.

The square root of 640555060 is about 25309.1892402740. The cubic root of 640555060 is about 862.0229374660.

The spelling of 640555060 in words is "six hundred forty million, five hundred fifty-five thousand, sixty".