643525456 has 40 divisors (see below), whose sum is σ = 1426587264. Its totient is φ = 275479680.

The previous prime is 643525411. The next prime is 643525489. The reversal of 643525456 is 654525346.

It is a happy number.

643525456 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 (40) coincides with the sum of the digits of its prime factors.

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, 112686 + ... + 118258.

Almost surely, 2^643525456 is an apocalyptic number.

It is an amenable number.

643525456 is an abundant number, since it is smaller than the sum of its proper divisors (783061808).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643525456 is a wasteful number, since it uses less digits than its factorization.

643525456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6619 (or 6613 counting only the distinct ones).

The product of its digits is 432000, while the sum is 40.

The square root of 643525456 is about 25367.8035312480. The cubic root of 643525456 is about 863.3533470148.

The spelling of 643525456 in words is "six hundred forty-three million, five hundred twenty-five thousand, four hundred fifty-six".