6665820 has 96 divisors (see below), whose sum is σ = 21772800. Its totient is φ = 1492224.

The previous prime is 6665803. The next prime is 6665831. The reversal of 6665820 is 285666.

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 31 ways as a sum of consecutive naturals, for example, 24646 + ... + 24914.

It is an arithmetic number, because the mean of its divisors is an integer number (226800).

Almost surely, 2^6665820 is an apocalyptic number.

6665820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6665820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10886400).

6665820 is an abundant number, since it is smaller than the sum of its proper divisors (15106980).

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

6665820 is a wasteful number, since it uses less digits than its factorization.

6665820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347 (or 345 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 6665820 is about 2581.8249359707. The cubic root of 6665820 is about 188.1992380005.

The spelling of 6665820 in words is "six million, six hundred sixty-five thousand, eight hundred twenty".