171491 has 2 divisors, whose sum is σ = 171492.
Its totient is φ = 171490.
The previous prime is 171481. The next prime is 171517. The reversal of 171491 is 194171.
It is a weak prime.
It is a cyclic number.
It is not a de Polignac number, because 171491 - 26 = 171427 is a prime.
It is a Chen prime.
It is not a weakly prime, because it can be changed into another prime (171401) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85745 + 85746.
It is an arithmetic number, because the mean of its divisors is an integer number (85746).
2171491 is an apocalyptic number.
171491 is a deficient number, since it is larger than the sum of its proper divisors (1).
171491 is an equidigital number, since it uses as much as digits as its factorization.
171491 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 252, while the sum is 23.
The square root of 171491 is about 414.1147184054.
The cubic root of 171491 is about 55.5580649237.
The spelling of 171491 in words is "one hundred seventy-one thousand, four hundred ninety-one".