643543412556 has 192 divisors, whose sum is σ = 1817128857600. Its totient is φ = 174965472000.

The previous prime is 643543412521. The next prime is 643543412563. The reversal of 643543412556 is 655214345346.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5770855 + ... + 5881313.

It is an arithmetic number, because the mean of its divisors is an integer number (9464212800).

Almost surely, 2^643543412556 is an apocalyptic number.

643543412556 is a gapful number since it is divisible by the number (66) 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 643543412556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (908564428800).

643543412556 is an abundant number, since it is smaller than the sum of its proper divisors (1173585445044).

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

643543412556 is a wasteful number, since it uses less digits than its factorization.

643543412556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110620 (or 110618 counting only the distinct ones).

The product of its digits is 5184000, while the sum is 48.

The spelling of 643543412556 in words is "six hundred forty-three billion, five hundred forty-three million, four hundred twelve thousand, five hundred fifty-six".