3665666665 has 8 divisors (see below), whose sum is σ = 4421130120. Its totient is φ = 2917646592.

The previous prime is 3665666663. The next prime is 3665666687. The reversal of 3665666665 is 5666665663.

It can be written as a sum of positive squares in 4 ways, for example, as 1132457104 + 2533209561 = 33652^2 + 50331^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 3665666665 - 2¹ = 3665666663 is a prime.

It is a super-2 number, since 2×3665666665² = 26874224197784444450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3665666663) 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, 1859760 + ... + 1861729.

It is an arithmetic number, because the mean of its divisors is an integer number (552641265).

Almost surely, 2^3665666665 is an apocalyptic number.

It is an amenable number.

3665666665 is a deficient number, since it is larger than the sum of its proper divisors (755463455).

3665666665 is a wasteful number, since it uses less digits than its factorization.

3665666665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3721691.

The product of its digits is 20995200, while the sum is 55.

The square root of 3665666665 is about 60544.7492768778. The cubic root of 3665666665 is about 1541.8814729598.

The spelling of 3665666665 in words is "three billion, six hundred sixty-five million, six hundred sixty-six thousand, six hundred sixty-five".