6638656 has 28 divisors (see below), whose sum is σ = 13459968. Its totient is φ = 3247232.

The previous prime is 6638647. The next prime is 6638669. The reversal of 6638656 is 6568366.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1905 + ... + 4111.

Almost surely, 2^6638656 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 6638656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6729984).

6638656 is an abundant number, since it is smaller than the sum of its proper divisors (6821312).

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

6638656 is a wasteful number, since it uses less digits than its factorization.

6638656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2266 (or 2256 counting only the distinct ones).

The product of its digits is 155520, while the sum is 40.

The square root of 6638656 is about 2576.5589455706. The cubic root of 6638656 is about 187.9432452796.

The spelling of 6638656 in words is "six million, six hundred thirty-eight thousand, six hundred fifty-six".