643085406 has 24 divisors (see below), whose sum is σ = 1444958424. Its totient is φ = 214361640.

The previous prime is 643085389. The next prime is 643085407. The reversal of 643085406 is 604580346.

643085406 is a `hidden beast` number, since 643 + 0 + 8 + 5 + 4 + 0 + 6 = 666.

643085406 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643085407) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 661125 + ... + 662096.

It is an arithmetic number, because the mean of its divisors is an integer number (60206601).

Almost surely, 2^643085406 is an apocalyptic number.

643085406 is an abundant number, since it is smaller than the sum of its proper divisors (801873018).

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

643085406 is a wasteful number, since it uses less digits than its factorization.

643085406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323238 (or 1323226 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 643085406 is about 25359.1286522230. The cubic root of 643085406 is about 863.1565118742.

The spelling of 643085406 in words is "six hundred forty-three million, eighty-five thousand, four hundred six".