6640768 has 32 divisors (see below), whose sum is σ = 13693500. Its totient is φ = 3204096.

The previous prime is 6640759. The next prime is 6640769. The reversal of 6640768 is 8670466.

It can be written as a sum of positive squares in 2 ways, for example, as 6110784 + 529984 = 2472^2 + 728^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (6640769) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2818 + ... + 4606.

Almost surely, 2^6640768 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6640768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6846750).

6640768 is an abundant number, since it is smaller than the sum of its proper divisors (7052732).

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

6640768 is a wasteful number, since it uses less digits than its factorization.

6640768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1832 (or 1820 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 37.

The square root of 6640768 is about 2576.9687619372. The cubic root of 6640768 is about 187.9631737133.

The spelling of 6640768 in words is "six million, six hundred forty thousand, seven hundred sixty-eight".