643523642 has 8 divisors (see below), whose sum is σ = 965744832. Its totient is φ = 321608700.

The previous prime is 643523641. The next prime is 643523687. The reversal of 643523642 is 246325346.

643523642 is nontrivially palindromic in base 5.

643523642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not an unprimeable number, because it can be changed into a prime (643523641) 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, 71234 + ... + 79757.

It is an arithmetic number, because the mean of its divisors is an integer number (120718104).

Almost surely, 2^643523642 is an apocalyptic number.

643523642 is a deficient number, since it is larger than the sum of its proper divisors (322221190).

643523642 is a wasteful number, since it uses less digits than its factorization.

643523642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153124.

The product of its digits is 103680, while the sum is 35.

The square root of 643523642 is about 25367.7677772405. The cubic root of 643523642 is about 863.3525357936.

Adding to 643523642 its reverse (246325346), we get a palindrome (889848988).

The spelling of 643523642 in words is "six hundred forty-three million, five hundred twenty-three thousand, six hundred forty-two".