643256260 has 12 divisors (see below), whose sum is σ = 1350838188. Its totient is φ = 257302496.

The previous prime is 643256239. The next prime is 643256261. The reversal of 643256260 is 62652346.

It can be written as a sum of positive squares in 2 ways, for example, as 454798276 + 188457984 = 21326^2 + 13728^2 .

It is not an unprimeable number, because it can be changed into a prime (643256261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16081387 + ... + 16081426.

It is an arithmetic number, because the mean of its divisors is an integer number (112569849).

Almost surely, 2^643256260 is an apocalyptic number.

It is an amenable number.

643256260 is an abundant number, since it is smaller than the sum of its proper divisors (707581928).

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

643256260 is a wasteful number, since it uses less digits than its factorization.

643256260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32162822 (or 32162820 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 34.

The square root of 643256260 is about 25362.4971168061. The cubic root of 643256260 is about 863.2329458300.

The spelling of 643256260 in words is "six hundred forty-three million, two hundred fifty-six thousand, two hundred sixty".