171339991 has 4 divisors (see below), whose sum is σ = 181418832. Its totient is φ = 161261152.

The previous prime is 171339983. The next prime is 171340003. The reversal of 171339991 is 199933171.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 171339991 - 2³ = 171339983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (171339491) 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, 5039395 + ... + 5039428.

It is an arithmetic number, because the mean of its divisors is an integer number (45354708).

Almost surely, 2^171339991 is an apocalyptic number.

171339991 is a deficient number, since it is larger than the sum of its proper divisors (10078841).

171339991 is a wasteful number, since it uses less digits than its factorization.

171339991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10078840.

The product of its digits is 45927, while the sum is 43.

The square root of 171339991 is about 13089.6902560756. The cubic root of 171339991 is about 555.4175263595.

The spelling of 171339991 in words is "one hundred seventy-one million, three hundred thirty-nine thousand, nine hundred ninety-one".