6447535668 has 216 divisors, whose sum is σ = 19925115392. Its totient is φ = 1721668608.

The previous prime is 6447535663. The next prime is 6447535681. The reversal of 6447535668 is 8665357446.

6447535668 is a `hidden beast` number, since 6 + 4 + 4 + 75 + 3 + 566 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6447535663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 16240446 + ... + 16240842.

Almost surely, 2^6447535668 is an apocalyptic number.

6447535668 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6447535668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9962557696).

6447535668 is an abundant number, since it is smaller than the sum of its proper divisors (13477579724).

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

6447535668 is a wasteful number, since it uses less digits than its factorization.

6447535668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671 (or 649 counting only the distinct ones).

The product of its digits is 14515200, while the sum is 54.

The square root of 6447535668 is about 80296.5482944317. The cubic root of 6447535668 is about 1861.2208876574.

The spelling of 6447535668 in words is "six billion, four hundred forty-seven million, five hundred thirty-five thousand, six hundred sixty-eight".