6641665 has 8 divisors (see below), whose sum is σ = 8005608. Its totient is φ = 5289600.

The previous prime is 6641633. The next prime is 6641669. The reversal of 6641665 is 5661466.

It can be written as a sum of positive squares in 4 ways, for example, as 804609 + 5837056 = 897^2 + 2416^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6641665 - 2⁵ = 6641633 is a prime.

It is a super-2 number, since 2×6641665² = 88223427944450, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6641665.

It is not an unprimeable number, because it can be changed into a prime (6641669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1686 + ... + 4015.

It is an arithmetic number, because the mean of its divisors is an integer number (1000701).

Almost surely, 2^6641665 is an apocalyptic number.

It is an amenable number.

6641665 is a deficient number, since it is larger than the sum of its proper divisors (1363943).

6641665 is a wasteful number, since it uses less digits than its factorization.

6641665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5939.

The product of its digits is 25920, while the sum is 34.

The square root of 6641665 is about 2577.1427977510. The cubic root of 6641665 is about 187.9716363578.

The spelling of 6641665 in words is "six million, six hundred forty-one thousand, six hundred sixty-five".