6643144420 has 72 divisors (see below), whose sum is σ = 16141305600. Its totient is φ = 2288531520.

The previous prime is 6643144399. The next prime is 6643144429. The reversal of 6643144420 is 244413466.

It is not an unprimeable number, because it can be changed into a prime (6643144429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26260 + ... + 118219.

It is an arithmetic number, because the mean of its divisors is an integer number (224184800).

Almost surely, 2^6643144420 is an apocalyptic number.

It is an amenable number.

6643144420 is an abundant number, since it is smaller than the sum of its proper divisors (9498161180).

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

6643144420 is a wasteful number, since it uses less digits than its factorization.

6643144420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144529 (or 144516 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 34.

The square root of 6643144420 is about 81505.4870545536. The cubic root of 6643144420 is about 1879.8559211298.

Adding to 6643144420 its reverse (244413466), we get a palindrome (6887557886).

The spelling of 6643144420 in words is "six billion, six hundred forty-three million, one hundred forty-four thousand, four hundred twenty".