171989539 has 4 divisors (see below), whose sum is σ = 181041640. Its totient is φ = 162937440.

The previous prime is 171989513. The next prime is 171989549. The reversal of 171989539 is 935989171.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 935989171 = 13 ⋅71999167.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-171989539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (171989549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4526022 + ... + 4526059.

It is an arithmetic number, because the mean of its divisors is an integer number (45260410).

Almost surely, 2^171989539 is an apocalyptic number.

171989539 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

171989539 is a deficient number, since it is larger than the sum of its proper divisors (9052101).

171989539 is an equidigital number, since it uses as much as digits as its factorization.

171989539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9052100.

The product of its digits is 612360, while the sum is 52.

The square root of 171989539 is about 13114.4782206537. The cubic root of 171989539 is about 556.1185018623.

The spelling of 171989539 in words is "one hundred seventy-one million, nine hundred eighty-nine thousand, five hundred thirty-nine".