665678742380171 has 16 divisors (see below), whose sum is σ = 722136225789888. Its totient is φ = 609971694912000.

The previous prime is 665678742380153. The next prime is 665678742380177. The reversal of 665678742380171 is 171083247876566.

It is a cyclic number.

It is not a de Polignac number, because 665678742380171 - 2¹⁴ = 665678742363787 is a prime.

It is a Smith number, since the sum of its digits (71) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 665678742380095 and 665678742380104.

It is not an unprimeable number, because it can be changed into a prime (665678742380177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64269071 + ... + 73904471.

It is an arithmetic number, because the mean of its divisors is an integer number (45133514111868).

Almost surely, 2^{665678742380171} is an apocalyptic number.

665678742380171 is a deficient number, since it is larger than the sum of its proper divisors (56457483409717).

665678742380171 is a wasteful number, since it uses less digits than its factorization.

665678742380171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9674342.

The product of its (nonzero) digits is 568995840, while the sum is 71.

The spelling of 665678742380171 in words is "six hundred sixty-five trillion, six hundred seventy-eight billion, seven hundred forty-two million, three hundred eighty thousand, one hundred seventy-one".