640857288240 has 480 divisors, whose sum is σ = 2516088960000. Its totient is φ = 149445264384.

The previous prime is 640857288187. The next prime is 640857288241. The reversal of 640857288240 is 42882758046.

640857288240 is a `hidden beast` number, since 6 + 40 + 8 + 572 + 8 + 8 + 24 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (640857288241) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6889561 + ... + 6981959.

It is an arithmetic number, because the mean of its divisors is an integer number (5241852000).

Almost surely, 2^640857288240 is an apocalyptic number.

640857288240 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 640857288240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1258044480000).

640857288240 is an abundant number, since it is smaller than the sum of its proper divisors (1875231671760).

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

640857288240 is a wasteful number, since it uses less digits than its factorization.

640857288240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92466 (or 92441 counting only the distinct ones).

The product of its (nonzero) digits is 6881280, while the sum is 54.

The spelling of 640857288240 in words is "six hundred forty billion, eight hundred fifty-seven million, two hundred eighty-eight thousand, two hundred forty".