665434512845 has 4 divisors (see below), whose sum is σ = 798521415420. Its totient is φ = 532347610272.

The previous prime is 665434512833. The next prime is 665434512871. The reversal of 665434512845 is 548215434566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 548215434566 = 2 ⋅274107717283.

It can be written as a sum of positive squares in 2 ways, for example, as 77246752489 + 588187760356 = 277933^2 + 766934^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665434512845 is a prime.

It is a Curzon 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, 66543451280 + ... + 66543451289.

It is an arithmetic number, because the mean of its divisors is an integer number (199630353855).

Almost surely, 2^665434512845 is an apocalyptic number.

It is an amenable number.

665434512845 is a deficient number, since it is larger than the sum of its proper divisors (133086902575).

665434512845 is a wasteful number, since it uses less digits than its factorization.

665434512845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133086902574.

The product of its digits is 13824000, while the sum is 53.

The spelling of 665434512845 in words is "six hundred sixty-five billion, four hundred thirty-four million, five hundred twelve thousand, eight hundred forty-five".