6640506 has 24 divisors (see below), whose sum is σ = 15234804. Its totient is φ = 2083200.

The previous prime is 6640499. The next prime is 6640511. The reversal of 6640506 is 6050466.

It can be written as a sum of positive squares in 2 ways, for example, as 5803281 + 837225 = 2409^2 + 915^2 .

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 6640506.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10545 + ... + 11156.

Almost surely, 2^6640506 is an apocalyptic number.

6640506 is an abundant number, since it is smaller than the sum of its proper divisors (8594298).

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

6640506 is a wasteful number, since it uses less digits than its factorization.

6640506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21726 (or 21723 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 6640506 is about 2576.9179265161. The cubic root of 6640506 is about 187.9607017603.

The spelling of 6640506 in words is "six million, six hundred forty thousand, five hundred six".