6681388 has 36 divisors (see below), whose sum is σ = 14124432. Its totient is φ = 2708640.

The previous prime is 6681377. The next prime is 6681403. The reversal of 6681388 is 8831866.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 6681388.

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, 9778 + ... + 10438.

Almost surely, 2^6681388 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 6681388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7062216).

6681388 is an abundant number, since it is smaller than the sum of its proper divisors (7443044).

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

6681388 is a wasteful number, since it uses less digits than its factorization.

6681388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710 (or 689 counting only the distinct ones).

The product of its digits is 55296, while the sum is 40.

The square root of 6681388 is about 2584.8380993788. The cubic root of 6681388 is about 188.3456369822.

The spelling of 6681388 in words is "six million, six hundred eighty-one thousand, three hundred eighty-eight".