643785587346 has 64 divisors (see below), whose sum is σ = 1426237747200. Its totient is φ = 192104732160.

The previous prime is 643785587317. The next prime is 643785587363.

643785587346 is nontrivially palindromic in base 10.

643785587346 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1021335 + ... + 1526661.

It is an arithmetic number, because the mean of its divisors is an integer number (22284964800).

Almost surely, 2^643785587346 is an apocalyptic number.

643785587346 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 643785587346, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (713118873600).

643785587346 is an abundant number, since it is smaller than the sum of its proper divisors (782452159854).

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

643785587346 is a wasteful number, since it uses less digits than its factorization.

643785587346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 505639.

The product of its digits is 406425600, while the sum is 66.

The spelling of 643785587346 in words is "six hundred forty-three billion, seven hundred eighty-five million, five hundred eighty-seven thousand, three hundred forty-six".