1665663355717 has 2 divisors, whose sum is σ = 1665663355718. Its totient is φ = 1665663355716.

The previous prime is 1665663355649. The next prime is 1665663355751. The reversal of 1665663355717 is 7175533665661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1633043744836 + 32619610881 = 1277906^2 + 180609^2 .

It is a cyclic number.

It is not a de Polignac number, because 1665663355717 - 2¹⁵ = 1665663322949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1665663355417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832831677858 + 832831677859.

It is an arithmetic number, because the mean of its divisors is an integer number (832831677859).

Almost surely, 2^{1665663355717} is an apocalyptic number.

It is an amenable number.

1665663355717 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665663355717 is an equidigital number, since it uses as much as digits as its factorization.

1665663355717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 71442000, while the sum is 61.

The spelling of 1665663355717 in words is "one trillion, six hundred sixty-five billion, six hundred sixty-three million, three hundred fifty-five thousand, seven hundred seventeen".