665601267617 has 16 divisors (see below), whose sum is σ = 787934347200. Its totient is φ = 554282788800.

The previous prime is 665601267589. The next prime is 665601267641. The reversal of 665601267617 is 716762106566.

It is not a de Polignac number, because 665601267617 - 2⁸ = 665601267361 is a prime.

It is not an unprimeable number, because it can be changed into a prime (665601267677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17746742 + ... + 17784207.

It is an arithmetic number, because the mean of its divisors is an integer number (49245896700).

Almost surely, 2^665601267617 is an apocalyptic number.

It is an amenable number.

665601267617 is a deficient number, since it is larger than the sum of its proper divisors (122333079583).

665601267617 is a wasteful number, since it uses less digits than its factorization.

665601267617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35531104.

The product of its (nonzero) digits is 3810240, while the sum is 53.

The spelling of 665601267617 in words is "six hundred sixty-five billion, six hundred one million, two hundred sixty-seven thousand, six hundred seventeen".