640385679360 has 1152 divisors, whose sum is σ = 2576970547200. Its totient is φ = 132498063360.

The previous prime is 640385679319. The next prime is 640385679361. The reversal of 640385679360 is 63976583046.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a self number, because there is not a number n which added to its sum of digits gives 640385679360.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640385679361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8106147801 + ... + 8106147879.

It is an arithmetic number, because the mean of its divisors is an integer number (2236953600).

Almost surely, 2^640385679360 is an apocalyptic number.

640385679360 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 640385679360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1288485273600).

640385679360 is an abundant number, since it is smaller than the sum of its proper divisors (1936584867840).

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

640385679360 is an equidigital number, since it uses as much as digits as its factorization.

640385679360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 19595520, while the sum is 57.

The spelling of 640385679360 in words is "six hundred forty billion, three hundred eighty-five million, six hundred seventy-nine thousand, three hundred sixty".