643875311 has 4 divisors (see below), whose sum is σ = 643938672. Its totient is φ = 643811952.

The previous prime is 643875307. The next prime is 643875373. The reversal of 643875311 is 113578346.

643875311 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 643875311 - 2² = 643875307 is a prime.

It is a super-2 number, since 2×643875311² = 829150832230693442, 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 (643875511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12611 + ... + 38036.

It is an arithmetic number, because the mean of its divisors is an integer number (160984668).

Almost surely, 2^643875311 is an apocalyptic number.

643875311 is a deficient number, since it is larger than the sum of its proper divisors (63361).

643875311 is a wasteful number, since it uses less digits than its factorization.

643875311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63360.

The product of its digits is 60480, while the sum is 38.

The square root of 643875311 is about 25374.6982445112. The cubic root of 643875311 is about 863.5097737535.

The spelling of 643875311 in words is "six hundred forty-three million, eight hundred seventy-five thousand, three hundred eleven".