171861983 has 4 divisors (see below), whose sum is σ = 172122648. Its totient is φ = 171601320.

The previous prime is 171861971. The next prime is 171861997. The reversal of 171861983 is 389168171.

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 171861983 - 2⁶ = 171861919 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (171861953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129341 + ... + 130662.

It is an arithmetic number, because the mean of its divisors is an integer number (43030662).

Almost surely, 2^171861983 is an apocalyptic number.

171861983 is a deficient number, since it is larger than the sum of its proper divisors (260665).

171861983 is an equidigital number, since it uses as much as digits as its factorization.

171861983 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260664.

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

The square root of 171861983 is about 13109.6141438259. The cubic root of 171861983 is about 555.9809861431.

The spelling of 171861983 in words is "one hundred seventy-one million, eight hundred sixty-one thousand, nine hundred eighty-three".