165243680717 has 4 divisors (see below), whose sum is σ = 165668472060. Its totient is φ = 164818889376.

The previous prime is 165243680669. The next prime is 165243680737. The reversal of 165243680717 is 717086342561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 717086342561 = 365377 ⋅1962593.

It can be written as a sum of positive squares in 2 ways, for example, as 85467937801 + 79775742916 = 292349^2 + 282446^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165243680717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165243680737) 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, 212395088 + ... + 212395865.

It is an arithmetic number, because the mean of its divisors is an integer number (41417118015).

Almost surely, 2^165243680717 is an apocalyptic number.

It is an amenable number.

165243680717 is a deficient number, since it is larger than the sum of its proper divisors (424791343).

165243680717 is an equidigital number, since it uses as much as digits as its factorization.

165243680717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424791342.

The product of its (nonzero) digits is 1693440, while the sum is 50.

The spelling of 165243680717 in words is "one hundred sixty-five billion, two hundred forty-three million, six hundred eighty thousand, seven hundred seventeen".