643104555844 has 27 divisors (see below), whose sum is σ = 1156778907543. Its totient is φ = 312832806048.

The previous prime is 643104555833. The next prime is 643104555871. The reversal of 643104555844 is 448555401346.

The square root of 643104555844 is 801938.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 14318994244 + 628785561600 = 119662^2 + 792960^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 59337994 + ... + 59348830.

Almost surely, 2^643104555844 is an apocalyptic number.

643104555844 is the 801938-th square number.

It is an amenable number.

643104555844 is a deficient number, since it is larger than the sum of its proper divisors (513674351699).

643104555844 is an frugal number, since it uses more digits than its factorization.

643104555844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21752 (or 10876 counting only the distinct ones).

The product of its (nonzero) digits is 4608000, while the sum is 49.

Multiplying 643104555844 by its sum of digits (49), we get a square (31512123236356 = 5613566²).

The spelling of 643104555844 in words is "six hundred forty-three billion, one hundred four million, five hundred fifty-five thousand, eight hundred forty-four".