171705139 has 2 divisors, whose sum is σ = 171705140. Its totient is φ = 171705138.

The previous prime is 171705137. The next prime is 171705161. The reversal of 171705139 is 931507171.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 171705139 - 2¹ = 171705137 is a prime.

Together with 171705137, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (171705133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85852569 + 85852570.

It is an arithmetic number, because the mean of its divisors is an integer number (85852570).

Almost surely, 2^171705139 is an apocalyptic number.

171705139 is a deficient number, since it is larger than the sum of its proper divisors (1).

171705139 is an equidigital number, since it uses as much as digits as its factorization.

171705139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6615, while the sum is 34.

The square root of 171705139 is about 13103.6307563973. The cubic root of 171705139 is about 555.8118022799.

The spelling of 171705139 in words is "one hundred seventy-one million, seven hundred five thousand, one hundred thirty-nine".