643403875 has 16 divisors (see below), whose sum is σ = 804259872. Its totient is φ = 513895200.

The previous prime is 643403861. The next prime is 643403921. The reversal of 643403875 is 578304346.

It is not a de Polignac number, because 643403875 - 2²⁹ = 106532963 is a prime.

It is a Duffinian 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 15 ways as a sum of consecutive naturals, for example, 80824 + ... + 88426.

It is an arithmetic number, because the mean of its divisors is an integer number (50266242).

Almost surely, 2^643403875 is an apocalyptic number.

643403875 is a deficient number, since it is larger than the sum of its proper divisors (160855997).

643403875 is an equidigital number, since it uses as much as digits as its factorization.

643403875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8295 (or 8285 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 40.

The square root of 643403875 is about 25365.4070537021. The cubic root of 643403875 is about 863.2989725926.

The spelling of 643403875 in words is "six hundred forty-three million, four hundred three thousand, eight hundred seventy-five".