643899830 has 16 divisors (see below), whose sum is σ = 1324594080. Its totient is φ = 220765632.

The previous prime is 643899827. The next prime is 643899869. The reversal of 643899830 is 38998346.

It is a congruent number.

It is an unprimeable number.

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, 4599215 + ... + 4599354.

It is an arithmetic number, because the mean of its divisors is an integer number (82787130).

Almost surely, 2^643899830 is an apocalyptic number.

643899830 is an abundant number, since it is smaller than the sum of its proper divisors (680694250).

643899830 is a wasteful number, since it uses less digits than its factorization.

643899830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9198583.

The product of its (nonzero) digits is 1119744, while the sum is 50.

The square root of 643899830 is about 25375.1813786621. The cubic root of 643899830 is about 863.5207345338.

The spelling of 643899830 in words is "six hundred forty-three million, eight hundred ninety-nine thousand, eight hundred thirty".