643506594 has 16 divisors (see below), whose sum is σ = 1287642720. Its totient is φ = 214397280.

The previous prime is 643506571. The next prime is 643506599. The reversal of 643506594 is 495605346.

It is not an unprimeable number, because it can be changed into a prime (643506599) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12379 + ... + 37950.

It is an arithmetic number, because the mean of its divisors is an integer number (80477670).

Almost surely, 2^643506594 is an apocalyptic number.

643506594 is an abundant number, since it is smaller than the sum of its proper divisors (644136126).

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

643506594 is a wasteful number, since it uses less digits than its factorization.

643506594 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52465.

The product of its (nonzero) digits is 388800, while the sum is 42.

The square root of 643506594 is about 25367.4317580633. The cubic root of 643506594 is about 863.3449118499.

The spelling of 643506594 in words is "six hundred forty-three million, five hundred six thousand, five hundred ninety-four".