665799165 has 12 divisors (see below), whose sum is σ = 1154051964. Its totient is φ = 355092864.

The previous prime is 665799119. The next prime is 665799181. The reversal of 665799165 is 561997566.

665799165 is a `hidden beast` number, since 6 + 6 + 579 + 9 + 1 + 65 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 238054041 + 427745124 = 15429^2 + 20682^2 .

It is not a de Polignac number, because 665799165 - 2¹⁰ = 665798141 is a prime.

It is a super-3 number, since 3×665799165³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7397724 + ... + 7397813.

It is an arithmetic number, because the mean of its divisors is an integer number (96170997).

Almost surely, 2^665799165 is an apocalyptic number.

It is an amenable number.

665799165 is a deficient number, since it is larger than the sum of its proper divisors (488252799).

665799165 is a wasteful number, since it uses less digits than its factorization.

665799165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14795548 (or 14795545 counting only the distinct ones).

The product of its digits is 3061800, while the sum is 54.

The square root of 665799165 is about 25803.0844086516. The cubic root of 665799165 is about 873.2013840076.

The spelling of 665799165 in words is "six hundred sixty-five million, seven hundred ninety-nine thousand, one hundred sixty-five".