665128116643 has 4 divisors (see below), whose sum is σ = 668058196680. Its totient is φ = 662198036608.

The previous prime is 665128116629. The next prime is 665128116673. The reversal of 665128116643 is 346611821566.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 665128116643 - 2³³ = 656538182051 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665128116623) 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, 1465039678 + ... + 1465040131.

It is an arithmetic number, because the mean of its divisors is an integer number (167014549170).

Almost surely, 2^665128116643 is an apocalyptic number.

665128116643 is a deficient number, since it is larger than the sum of its proper divisors (2930080037).

665128116643 is a wasteful number, since it uses less digits than its factorization.

665128116643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2930080036.

The product of its digits is 1244160, while the sum is 49.

The spelling of 665128116643 in words is "six hundred sixty-five billion, one hundred twenty-eight million, one hundred sixteen thousand, six hundred forty-three".