171989 has 8 divisors (see below), whose sum is σ = 186048. Its totient is φ = 158400.

The previous prime is 171947. The next prime is 172001. The reversal of 171989 is 989171.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 171989 - 2⁸ = 171733 is a prime.

It is a super-2 number, since 2×171989² = 59160432242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (171929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1064 + ... + 1214.

It is an arithmetic number, because the mean of its divisors is an integer number (23256).

2¹⁷¹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

171989 is a deficient number, since it is larger than the sum of its proper divisors (14059).

171989 is a wasteful number, since it uses less digits than its factorization.

171989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235.

The product of its digits is 4536, while the sum is 35.

The square root of 171989 is about 414.7155651769. The cubic root of 171989 is about 55.6117920920.

The spelling of 171989 in words is "one hundred seventy-one thousand, nine hundred eighty-nine".