171665563 has 2 divisors, whose sum is σ = 171665564. Its totient is φ = 171665562.

The previous prime is 171665539. The next prime is 171665567. The reversal of 171665563 is 365566171.

It is a strong prime.

It is an emirp because it is prime and its reverse (365566171) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 171665563 - 2⁹ = 171665051 is a prime.

It is not a weakly prime, because it can be changed into another prime (171665567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85832781 + 85832782.

It is an arithmetic number, because the mean of its divisors is an integer number (85832782).

Almost surely, 2^171665563 is an apocalyptic number.

171665563 is a deficient number, since it is larger than the sum of its proper divisors (1).

171665563 is an equidigital number, since it uses as much as digits as its factorization.

171665563 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 113400, while the sum is 40.

The square root of 171665563 is about 13102.1205535593. The cubic root of 171665563 is about 555.7690963205.

The spelling of 171665563 in words is "one hundred seventy-one million, six hundred sixty-five thousand, five hundred sixty-three".