643606262208 has 672 divisors, whose sum is σ = 2302345229184. Its totient is φ = 167382319104.

The previous prime is 643606262197. The next prime is 643606262237. The reversal of 643606262208 is 802262606346.

643606262208 is a `hidden beast` number, since 6 + 4 + 360 + 6 + 262 + 20 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

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 95 ways as a sum of consecutive naturals, for example, 1621174266 + ... + 1621174662.

It is an arithmetic number, because the mean of its divisors is an integer number (3426108972).

Almost surely, 2^643606262208 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 643606262208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1151172614592).

643606262208 is an abundant number, since it is smaller than the sum of its proper divisors (1658738966976).

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

643606262208 is a wasteful number, since it uses less digits than its factorization.

643606262208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 789 (or 776 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 45.

The spelling of 643606262208 in words is "six hundred forty-three billion, six hundred six million, two hundred sixty-two thousand, two hundred eight".