6403643568 has 400 divisors, whose sum is σ = 22585221120. Its totient is φ = 1710968832.

The previous prime is 6403643563. The next prime is 6403643569. The reversal of 6403643568 is 8653463046.

6403643568 is a `hidden beast` number, since 6 + 40 + 3 + 6 + 43 + 568 = 666.

It is not an unprimeable number, because it can be changed into a prime (6403643563) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 16719505 + ... + 16719887.

Almost surely, 2^6403643568 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6403643568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11292610560).

6403643568 is an abundant number, since it is smaller than the sum of its proper divisors (16181577552).

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

6403643568 is a wasteful number, since it uses less digits than its factorization.

6403643568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 526 (or 511 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 45.

The square root of 6403643568 is about 80022.7690598120. The cubic root of 6403643568 is about 1856.9877987825.

The spelling of 6403643568 in words is "six billion, four hundred three million, six hundred forty-three thousand, five hundred sixty-eight".