643236542 has 16 divisors (see below), whose sum is σ = 1040091360. Its totient is φ = 296587872.

The previous prime is 643236523. The next prime is 643236551. The reversal of 643236542 is 245632346.

643236542 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16223 + ... + 39365.

It is an arithmetic number, because the mean of its divisors is an integer number (65005710).

Almost surely, 2^643236542 is an apocalyptic number.

643236542 is a deficient number, since it is larger than the sum of its proper divisors (396854818).

643236542 is a wasteful number, since it uses less digits than its factorization.

643236542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24227.

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

The square root of 643236542 is about 25362.1083902739. The cubic root of 643236542 is about 863.2241253944.

Adding to 643236542 its reverse (245632346), we get a palindrome (888868888).

The spelling of 643236542 in words is "six hundred forty-three million, two hundred thirty-six thousand, five hundred forty-two".