643541688 has 48 divisors (see below), whose sum is σ = 1775821320. Its totient is φ = 210465216.

The previous prime is 643541659. The next prime is 643541711. The reversal of 643541688 is 886145346.

643541688 is a `hidden beast` number, since 6 + 43 + 541 + 68 + 8 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 80506 + ... + 88137.

Almost surely, 2^643541688 is an apocalyptic number.

It is an amenable number.

643541688 is an abundant number, since it is smaller than the sum of its proper divisors (1132279632).

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

643541688 is a wasteful number, since it uses less digits than its factorization.

643541688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168708 (or 168701 counting only the distinct ones).

The product of its digits is 552960, while the sum is 45.

The square root of 643541688 is about 25368.1234623296. The cubic root of 643541688 is about 863.3606059008.

The spelling of 643541688 in words is "six hundred forty-three million, five hundred forty-one thousand, six hundred eighty-eight".