665516651052205 has 4 divisors (see below), whose sum is σ = 798619981262652. Its totient is φ = 532413320841760.

The previous prime is 665516651052079. The next prime is 665516651052251. The reversal of 665516651052205 is 502250156615566.

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 99350936640036 + 566165714412169 = 9967494^2 + 23794237^2 .

It is not a de Polignac number, because 665516651052205 - 2²⁹ = 665516114181293 is a prime.

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, 66551665105216 + ... + 66551665105225.

It is an arithmetic number, because the mean of its divisors is an integer number (199654995315663).

Almost surely, 2^{665516651052205} is an apocalyptic number.

It is an amenable number.

665516651052205 is a deficient number, since it is larger than the sum of its proper divisors (133103330210447).

665516651052205 is a wasteful number, since it uses less digits than its factorization.

665516651052205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133103330210446.

The product of its (nonzero) digits is 16200000, while the sum is 55.

The spelling of 665516651052205 in words is "six hundred sixty-five trillion, five hundred sixteen billion, six hundred fifty-one million, fifty-two thousand, two hundred five".