643403244 has 24 divisors (see below), whose sum is σ = 1637754048. Its totient is φ = 194970640.

The previous prime is 643403237. The next prime is 643403261. The reversal of 643403244 is 442304346.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2437002 + ... + 2437265.

It is an arithmetic number, because the mean of its divisors is an integer number (68239752).

Almost surely, 2^643403244 is an apocalyptic number.

It is an amenable number.

643403244 is an abundant number, since it is smaller than the sum of its proper divisors (994350804).

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

643403244 is a wasteful number, since it uses less digits than its factorization.

643403244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4874285 (or 4874283 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 30.

The square root of 643403244 is about 25365.3946154993. The cubic root of 643403244 is about 863.2986903739.

The spelling of 643403244 in words is "six hundred forty-three million, four hundred three thousand, two hundred forty-four".