6645888 has 80 divisors (see below), whose sum is σ = 19808910. Its totient is φ = 2211840.

The previous prime is 6645887. The next prime is 6645907. The reversal of 6645888 is 8885466.

6645888 is a `hidden beast` number, since 6 + 64 + 588 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 4359744 + 2286144 = 2088^2 + 1512^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6645883) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 10048 + ... + 10688.

Almost surely, 2^6645888 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 6645888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9904455).

6645888 is an abundant number, since it is smaller than the sum of its proper divisors (13163022).

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

6645888 is an equidigital number, since it uses as much as digits as its factorization.

6645888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667 (or 646 counting only the distinct ones).

The product of its digits is 368640, while the sum is 45.

The square root of 6645888 is about 2577.9619857554. The cubic root of 6645888 is about 188.0114675365.

It can be divided in two parts, 66 and 45888, that added together give a palindrome (45954).

The spelling of 6645888 in words is "six million, six hundred forty-five thousand, eight hundred eighty-eight".