640835580 has 192 divisors, whose sum is σ = 2275983360. Its totient is φ = 130848000.

The previous prime is 640835567. The next prime is 640835603. The reversal of 640835580 is 85538046.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 271405 + ... + 273755.

It is an arithmetic number, because the mean of its divisors is an integer number (11854080).

Almost surely, 2^640835580 is an apocalyptic number.

640835580 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640835580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1137991680).

640835580 is an abundant number, since it is smaller than the sum of its proper divisors (1635147780).

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

640835580 is a wasteful number, since it uses less digits than its factorization.

640835580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2440 (or 2438 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 39.

The square root of 640835580 is about 25314.7304943189. The cubic root of 640835580 is about 862.1487551089.

The spelling of 640835580 in words is "six hundred forty million, eight hundred thirty-five thousand, five hundred eighty".