643812551424 has 864 divisors, whose sum is σ = 2279903109120. Its totient is φ = 177394323456.

The previous prime is 643812551411. The next prime is 643812551467. The reversal of 643812551424 is 424155218346.

643812551424 is a `hidden beast` number, since 6 + 4 + 3 + 8 + 125 + 514 + 2 + 4 = 666.

643812551424 is digitally balanced in base 2, base 4 and base 7, because in such bases it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (864).

It is a self number, because there is not a number n which added to its sum of digits gives 643812551424.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1698713667 + ... + 1698714045.

Almost surely, 2^643812551424 is an apocalyptic number.

643812551424 is a gapful number since it is divisible by the number (64) 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 643812551424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1139951554560).

643812551424 is an abundant number, since it is smaller than the sum of its proper divisors (1636090557696).

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

643812551424 is an equidigital number, since it uses as much as digits as its factorization.

643812551424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 547 (or 521 counting only the distinct ones).

The product of its digits is 921600, while the sum is 45.

The spelling of 643812551424 in words is "six hundred forty-three billion, eight hundred twelve million, five hundred fifty-one thousand, four hundred twenty-four".