6643722544 has 20 divisors (see below), whose sum is σ = 12874529896. Its totient is φ = 3321263232.

The previous prime is 6643722521. The next prime is 6643722551. The reversal of 6643722544 is 4452273466.

It is a self number, because there is not a number n which added to its sum of digits gives 6643722544.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62332 + ... + 131044.

Almost surely, 2^6643722544 is an apocalyptic number.

It is an amenable number.

6643722544 is a deficient number, since it is larger than the sum of its proper divisors (6230807352).

6643722544 is a wasteful number, since it uses less digits than its factorization.

6643722544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74764 (or 74758 counting only the distinct ones).

The product of its digits is 967680, while the sum is 43.

The square root of 6643722544 is about 81509.0335116299. The cubic root of 6643722544 is about 1879.9104514462.

The spelling of 6643722544 in words is "six billion, six hundred forty-three million, seven hundred twenty-two thousand, five hundred forty-four".