171997 has 4 divisors (see below), whose sum is σ = 196576. Its totient is φ = 147420.

The previous prime is 171947. The next prime is 172001. The reversal of 171997 is 799171.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 171997 - 2⁷ = 171869 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 (171917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12279 + ... + 12292.

It is an arithmetic number, because the mean of its divisors is an integer number (49144).

2¹⁷¹⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

171997 is a deficient number, since it is larger than the sum of its proper divisors (24579).

171997 is an equidigital number, since it uses as much as digits as its factorization.

171997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24578.

The product of its digits is 3969, while the sum is 34.

The square root of 171997 is about 414.7252102296. The cubic root of 171997 is about 55.6126543321.

The spelling of 171997 in words is "one hundred seventy-one thousand, nine hundred ninety-seven".