640555084800 has 528 divisors, whose sum is σ = 2358772838400. Its totient is φ = 170344857600.

The previous prime is 640555084753. The next prime is 640555084831. The reversal of 640555084800 is 8480555046.

640555084800 is a `hidden beast` number, since 64 + 0 + 5 + 5 + 508 + 4 + 80 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 303435745 + ... + 303437855.

It is an arithmetic number, because the mean of its divisors is an integer number (4467372800).

Almost surely, 2^640555084800 is an apocalyptic number.

640555084800 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 640555084800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1179386419200).

640555084800 is an abundant number, since it is smaller than the sum of its proper divisors (1718217753600).

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

640555084800 is a wasteful number, since it uses less digits than its factorization.

640555084800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2589 (or 2560 counting only the distinct ones).

The product of its (nonzero) digits is 768000, while the sum is 45.

The spelling of 640555084800 in words is "six hundred forty billion, five hundred fifty-five million, eighty-four thousand, eight hundred".