643230999 has 12 divisors (see below), whose sum is σ = 929359912. Its totient is φ = 428706000.

The previous prime is 643230971. The next prime is 643231013. The reversal of 643230999 is 999032346.

It is not a de Polignac number, because 643230999 - 2⁵ = 643230967 is a prime.

It is a super-2 number, since 2×643230999² = 827492236149076002, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643230799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38904 + ... + 52914.

Almost surely, 2^643230999 is an apocalyptic number.

643230999 is a deficient number, since it is larger than the sum of its proper divisors (286128913).

643230999 is a wasteful number, since it uses less digits than its factorization.

643230999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19118 (or 19115 counting only the distinct ones).

The product of its (nonzero) digits is 314928, while the sum is 45.

The square root of 643230999 is about 25361.9991128460. Note that the first 3 decimals coincide. The cubic root of 643230999 is about 863.2216458166.

Adding to 643230999 its sum of digits (45), we get a square (643231044 = 25362²).

The spelling of 643230999 in words is "six hundred forty-three million, two hundred thirty thousand, nine hundred ninety-nine".