3665840665 has 16 divisors (see below), whose sum is σ = 4536036288. Its totient is φ = 2842655296.

The previous prime is 3665840621. The next prime is 3665840681. The reversal of 3665840665 is 5660485663.

It is a cyclic number.

It is not a de Polignac number, because 3665840665 - 2⁷ = 3665840537 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61339 + ... + 105328.

It is an arithmetic number, because the mean of its divisors is an integer number (283502268).

Almost surely, 2^3665840665 is an apocalyptic number.

It is an amenable number.

3665840665 is a deficient number, since it is larger than the sum of its proper divisors (870195623).

3665840665 is a wasteful number, since it uses less digits than its factorization.

3665840665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166808.

The product of its (nonzero) digits is 3110400, while the sum is 49.

The square root of 3665840665 is about 60546.1862135015. The cubic root of 3665840665 is about 1541.9058689889.

The spelling of 3665840665 in words is "three billion, six hundred sixty-five million, eight hundred forty thousand, six hundred sixty-five".