643523896 has 16 divisors (see below), whose sum is σ = 1234668600. Its totient is φ = 314278944.

The previous prime is 643523887. The next prime is 643523897. The reversal of 643523896 is 698325346.

It is a happy number.

643523896 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643523897) 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, 935011 + ... + 935698.

Almost surely, 2^643523896 is an apocalyptic number.

It is an amenable number.

643523896 is a deficient number, since it is larger than the sum of its proper divisors (591144704).

643523896 is a wasteful number, since it uses less digits than its factorization.

643523896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1870758 (or 1870754 counting only the distinct ones).

The product of its digits is 933120, while the sum is 46.

The square root of 643523896 is about 25367.7727835930. The cubic root of 643523896 is about 863.3526493826.

The spelling of 643523896 in words is "six hundred forty-three million, five hundred twenty-three thousand, eight hundred ninety-six".