643559143 has 4 divisors (see below), whose sum is σ = 643991688. Its totient is φ = 643126600.

The previous prime is 643559117. The next prime is 643559149. The reversal of 643559143 is 341955346.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 643559143 - 2⁹ = 643558631 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 643559096 and 643559105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643559149) 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, 214033 + ... + 217018.

It is an arithmetic number, because the mean of its divisors is an integer number (160997922).

Almost surely, 2^643559143 is an apocalyptic number.

643559143 is a deficient number, since it is larger than the sum of its proper divisors (432545).

643559143 is a wasteful number, since it uses less digits than its factorization.

643559143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432544.

The product of its digits is 194400, while the sum is 40.

The square root of 643559143 is about 25368.4674941156. The cubic root of 643559143 is about 863.3684115713.

The spelling of 643559143 in words is "six hundred forty-three million, five hundred fifty-nine thousand, one hundred forty-three".