643255305552 has 160 divisors (see below), whose sum is σ = 1877796956160. Its totient is φ = 210783323520.

The previous prime is 643255305541. The next prime is 643255305587. The reversal of 643255305552 is 255503552346.

It is a happy number.

643255305552 is a `hidden beast` number, since 6 + 43 + 2 + 5 + 53 + 0 + 5 + 552 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 643255305498 and 643255305507.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 14188873 + ... + 14234135.

It is an arithmetic number, because the mean of its divisors is an integer number (11736230976).

Almost surely, 2^643255305552 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643255305552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (938898478080).

643255305552 is an abundant number, since it is smaller than the sum of its proper divisors (1234541650608).

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

643255305552 is a wasteful number, since it uses less digits than its factorization.

643255305552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45838 (or 45826 counting only the distinct ones).

The product of its (nonzero) digits is 2700000, while the sum is 45.

Adding to 643255305552 its reverse (255503552346), we get a palindrome (898758857898).

The spelling of 643255305552 in words is "six hundred forty-three billion, two hundred fifty-five million, three hundred five thousand, five hundred fifty-two".