165605617 has 2 divisors, whose sum is σ = 165605618. Its totient is φ = 165605616.

The previous prime is 165605579. The next prime is 165605621. The reversal of 165605617 is 716506561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 116661601 + 48944016 = 10801^2 + 6996^2 .

It is a cyclic number.

It is not a de Polignac number, because 165605617 - 2¹¹ = 165603569 is a prime.

It is not a weakly prime, because it can be changed into another prime (165605677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82802808 + 82802809.

It is an arithmetic number, because the mean of its divisors is an integer number (82802809).

Almost surely, 2^165605617 is an apocalyptic number.

It is an amenable number.

165605617 is a deficient number, since it is larger than the sum of its proper divisors (1).

165605617 is an equidigital number, since it uses as much as digits as its factorization.

165605617 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37800, while the sum is 37.

The square root of 165605617 is about 12868.7845968452. The cubic root of 165605617 is about 549.1508848130.

The spelling of 165605617 in words is "one hundred sixty-five million, six hundred five thousand, six hundred seventeen".