3666665 has 4 divisors (see below), whose sum is σ = 4400004. Its totient is φ = 2933328.

The previous prime is 3666661. The next prime is 3666703. The reversal of 3666665 is 5666663.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5666663 = 1877 ⋅3019.

It can be written as a sum of positive squares in 2 ways, for example, as 614656 + 3052009 = 784^2 + 1747^2 .

It is a cyclic number.

It is not a de Polignac number, because 3666665 - 2² = 3666661 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (3666661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 366662 + ... + 366671.

It is an arithmetic number, because the mean of its divisors is an integer number (1100001).

Almost surely, 2^3666665 is an apocalyptic number.

It is an amenable number.

3666665 is a deficient number, since it is larger than the sum of its proper divisors (733339).

3666665 is an equidigital number, since it uses as much as digits as its factorization.

3666665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 733338.

The product of its digits is 116640, while the sum is 38.

The square root of 3666665 is about 1914.8537803185. The cubic root of 3666665 is about 154.2021436088.

The spelling of 3666665 in words is "three million, six hundred sixty-six thousand, six hundred sixty-five".