2666440165 has 4 divisors (see below), whose sum is σ = 3199728204. Its totient is φ = 2133152128.

The previous prime is 2666440141. The next prime is 2666440181. The reversal of 2666440165 is 5610446662.

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 1723827361 + 942612804 = 41519^2 + 30702^2 .

It is a cyclic number.

It is not a de Polignac number, because 2666440165 - 2⁷ = 2666440037 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266644012 + ... + 266644021.

It is an arithmetic number, because the mean of its divisors is an integer number (799932051).

Almost surely, 2^2666440165 is an apocalyptic number.

It is an amenable number.

2666440165 is a deficient number, since it is larger than the sum of its proper divisors (533288039).

2666440165 is an equidigital number, since it uses as much as digits as its factorization.

2666440165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 533288038.

The product of its (nonzero) digits is 207360, while the sum is 40.

The square root of 2666440165 is about 51637.5848099037. The cubic root of 2666440165 is about 1386.6832857185.

The spelling of 2666440165 in words is "two billion, six hundred sixty-six million, four hundred forty thousand, one hundred sixty-five".