6640868 has 12 divisors (see below), whose sum is σ = 12515580. Its totient is φ = 3064992.

The previous prime is 6640849. The next prime is 6640889. The reversal of 6640868 is 8680466.

It can be written as a sum of positive squares in 2 ways, for example, as 1721344 + 4919524 = 1312^2 + 2218^2 .

It is a super-2 number, since 2×6640868² = 88202255586848, which contains 22 as substring.

It is an unprimeable number.

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, 63803 + ... + 63906.

It is an arithmetic number, because the mean of its divisors is an integer number (1042965).

Almost surely, 2^6640868 is an apocalyptic number.

It is an amenable number.

6640868 is a deficient number, since it is larger than the sum of its proper divisors (5874712).

6640868 is a wasteful number, since it uses less digits than its factorization.

6640868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127726 (or 127724 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 38.

The square root of 6640868 is about 2576.9881645052. The cubic root of 6640868 is about 187.9641171897.

The spelling of 6640868 in words is "six million, six hundred forty thousand, eight hundred sixty-eight".