665518313 has 4 divisors (see below), whose sum is σ = 667403988. Its totient is φ = 663632640.

The previous prime is 665518307. The next prime is 665518327. The reversal of 665518313 is 313815566.

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 466905664 + 198612649 = 21608^2 + 14093^2 .

It is a cyclic number.

It is not a de Polignac number, because 665518313 - 2¹² = 665514217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665518813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 942308 + ... + 943013.

It is an arithmetic number, because the mean of its divisors is an integer number (166850997).

Almost surely, 2^665518313 is an apocalyptic number.

It is an amenable number.

665518313 is a deficient number, since it is larger than the sum of its proper divisors (1885675).

665518313 is a wasteful number, since it uses less digits than its factorization.

665518313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1885674.

The product of its digits is 64800, while the sum is 38.

The square root of 665518313 is about 25797.6416170161. The cubic root of 665518313 is about 873.0785867943.

The spelling of 665518313 in words is "six hundred sixty-five million, five hundred eighteen thousand, three hundred thirteen".