6643240 has 16 divisors (see below), whose sum is σ = 14947380. Its totient is φ = 2657280.

The previous prime is 6643229. The next prime is 6643249. The reversal of 6643240 is 423466.

It can be written as a sum of positive squares in 2 ways, for example, as 6461764 + 181476 = 2542^2 + 426^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6643249) 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 3 ways as a sum of consecutive naturals, for example, 83001 + ... + 83080.

Almost surely, 2^6643240 is an apocalyptic number.

It is an amenable number.

6643240 is an abundant number, since it is smaller than the sum of its proper divisors (8304140).

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

6643240 is a wasteful number, since it uses less digits than its factorization.

6643240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166092 (or 166088 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 6643240 is about 2577.4483505979. The cubic root of 6643240 is about 187.9864936728.

The spelling of 6643240 in words is "six million, six hundred forty-three thousand, two hundred forty".