6611665 has 4 divisors (see below), whose sum is σ = 7934004. Its totient is φ = 5289328.

The previous prime is 6611663. The next prime is 6611699. The reversal of 6611665 is 5661166.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4892944 + 1718721 = 2212^2 + 1311^2 .

It is a cyclic number.

It is not a de Polignac number, because 6611665 - 2¹ = 6611663 is a prime.

It is a super-2 number, since 2×6611665² = 87428228144450, which contains 22 as substring.

It is a Duffinian number.

6611665 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6611663) 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 3 ways as a sum of consecutive naturals, for example, 661162 + ... + 661171.

It is an arithmetic number, because the mean of its divisors is an integer number (1983501).

Almost surely, 2^6611665 is an apocalyptic number.

It is an amenable number.

6611665 is a deficient number, since it is larger than the sum of its proper divisors (1322339).

6611665 is a wasteful number, since it uses less digits than its factorization.

6611665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1322338.

The product of its digits is 6480, while the sum is 31.

The square root of 6611665 is about 2571.3158110197. The cubic root of 6611665 is about 187.6881903129.

The spelling of 6611665 in words is "six million, six hundred eleven thousand, six hundred sixty-five".