6639870 has 32 divisors (see below), whose sum is σ = 16630272. Its totient is φ = 1693472.

The previous prime is 6639863. The next prime is 6639881. The reversal of 6639870 is 789366.

It is a Curzon number.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 4122 + ... + 5501.

It is an arithmetic number, because the mean of its divisors is an integer number (519696).

Almost surely, 2^6639870 is an apocalyptic number.

6639870 is an abundant number, since it is smaller than the sum of its proper divisors (9990402).

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

6639870 is a wasteful number, since it uses less digits than its factorization.

6639870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9656.

The product of its (nonzero) digits is 54432, while the sum is 39.

The square root of 6639870 is about 2576.7945203295. The cubic root of 6639870 is about 187.9547008710.

The spelling of 6639870 in words is "six million, six hundred thirty-nine thousand, eight hundred seventy".