6665616 has 60 divisors (see below), whose sum is σ = 19126380. Its totient is φ = 2165760.

The previous prime is 6665611. The next prime is 6665623. The reversal of 6665616 is 6165666.

It can be written as a sum of positive squares in 2 ways, for example, as 435600 + 6230016 = 660^2 + 2496^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (6665611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5340 + ... + 6468.

It is an arithmetic number, because the mean of its divisors is an integer number (318773).

Almost surely, 2^6665616 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 6665616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9563190).

6665616 is an abundant number, since it is smaller than the sum of its proper divisors (12460764).

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

6665616 is a wasteful number, since it uses less digits than its factorization.

6665616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1184 (or 1175 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The square root of 6665616 is about 2581.7854287295. The cubic root of 6665616 is about 188.1973181049.

The spelling of 6665616 in words is "six million, six hundred sixty-five thousand, six hundred sixteen".