643436801280 has 1152 divisors, whose sum is σ = 2837516774400. Its totient is φ = 134440943616.

The previous prime is 643436801191. The next prime is 643436801311. The reversal of 643436801280 is 82108634346.

643436801280 is a `hidden beast` number, since 6 + 4 + 3 + 4 + 368 + 0 + 1 + 280 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 342799702 + ... + 342801578.

It is an arithmetic number, because the mean of its divisors is an integer number (2463122200).

Almost surely, 2^643436801280 is an apocalyptic number.

643436801280 is a gapful number since it is divisible by the number (60) 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 643436801280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1418758387200).

643436801280 is an abundant number, since it is smaller than the sum of its proper divisors (2194079973120).

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

643436801280 is a wasteful number, since it uses less digits than its factorization.

643436801280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2036 (or 2016 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 45.

The spelling of 643436801280 in words is "six hundred forty-three billion, four hundred thirty-six million, eight hundred one thousand, two hundred eighty".