171989171 has 4 divisors (see below), whose sum is σ = 172039344. Its totient is φ = 171939000.

The previous prime is 171989149. The next prime is 171989177.

171989171 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-171989171 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (171989177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19535 + ... + 26936.

It is an arithmetic number, because the mean of its divisors is an integer number (43009836).

Almost surely, 2^171989171 is an apocalyptic number.

171989171 is a deficient number, since it is larger than the sum of its proper divisors (50173).

171989171 is an equidigital number, since it uses as much as digits as its factorization.

171989171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50172.

The product of its digits is 31752, while the sum is 44.

The square root of 171989171 is about 13114.4641903510. The cubic root of 171989171 is about 556.1181052263.

The spelling of 171989171 in words is "one hundred seventy-one million, nine hundred eighty-nine thousand, one hundred seventy-one".