171868139 has 4 divisors (see below), whose sum is σ = 172042560. Its totient is φ = 171693720.

The previous prime is 171868127. The next prime is 171868223. The reversal of 171868139 is 931868171.

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 171868139 - 2²⁰ = 170819563 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 171868139.

It is not an unprimeable number, because it can be changed into a prime (171868339) 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, 85724 + ... + 87705.

It is an arithmetic number, because the mean of its divisors is an integer number (43010640).

Almost surely, 2^171868139 is an apocalyptic number.

171868139 is a deficient number, since it is larger than the sum of its proper divisors (174421).

171868139 is an equidigital number, since it uses as much as digits as its factorization.

171868139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174420.

The product of its digits is 72576, while the sum is 44.

The square root of 171868139 is about 13109.8489312425. The cubic root of 171868139 is about 555.9876243730.

The spelling of 171868139 in words is "one hundred seventy-one million, eight hundred sixty-eight thousand, one hundred thirty-nine".