6643280 has 40 divisors (see below), whose sum is σ = 17653632. Its totient is φ = 2277504.

The previous prime is 6643261. The next prime is 6643283. The reversal of 6643280 is 823466.

It is a tau number, because it is divible by the number of its divisors (40).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6643283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5372 + ... + 6491.

Almost surely, 2^6643280 is an apocalyptic number.

It is an amenable number.

6643280 is an abundant number, since it is smaller than the sum of its proper divisors (11010352).

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

6643280 is a wasteful number, since it uses less digits than its factorization.

6643280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11883 (or 11877 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 6643280 is about 2577.4561101986. The cubic root of 6643280 is about 187.9868709709.

The spelling of 6643280 in words is "six million, six hundred forty-three thousand, two hundred eighty".