6639556 has 24 divisors (see below), whose sum is σ = 14486976. Its totient is φ = 2586720.

The previous prime is 6639547. The next prime is 6639593. The reversal of 6639556 is 6559366.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10471 + ... + 11086.

It is an arithmetic number, because the mean of its divisors is an integer number (603624).

Almost surely, 2^6639556 is an apocalyptic number.

It is an amenable number.

6639556 is an abundant number, since it is smaller than the sum of its proper divisors (7847420).

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

6639556 is a wasteful number, since it uses less digits than its factorization.

6639556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21579 (or 21577 counting only the distinct ones).

The product of its digits is 145800, while the sum is 40.

The square root of 6639556 is about 2576.7335911964. The cubic root of 6639556 is about 187.9517380266.

The spelling of 6639556 in words is "six million, six hundred thirty-nine thousand, five hundred fifty-six".