643403873 has 8 divisors (see below), whose sum is σ = 743581440. Its totient is φ = 545292000.

The previous prime is 643403861. The next prime is 643403921. The reversal of 643403873 is 378304346.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 643403873 - 2¹² = 643399777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643403833) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 515753 + ... + 516998.

It is an arithmetic number, because the mean of its divisors is an integer number (92947680).

Almost surely, 2^643403873 is an apocalyptic number.

It is an amenable number.

643403873 is a deficient number, since it is larger than the sum of its proper divisors (100177567).

643403873 is a wasteful number, since it uses less digits than its factorization.

643403873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1032847.

The product of its (nonzero) digits is 145152, while the sum is 38.

The square root of 643403873 is about 25365.4070142783. The cubic root of 643403873 is about 863.2989716981.

The spelling of 643403873 in words is "six hundred forty-three million, four hundred three thousand, eight hundred seventy-three".