171956 has 6 divisors (see below), whose sum is σ = 300930. Its totient is φ = 85976.

The previous prime is 171947. The next prime is 172001. The reversal of 171956 is 659171.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 144400 + 27556 = 380^2 + 166^2 .

It is a congruent number.

It is an unprimeable number.

171956 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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, 21491 + ... + 21498.

It is an arithmetic number, because the mean of its divisors is an integer number (50155).

2¹⁷¹⁹⁵⁶ is an apocalyptic number.

It is an amenable number.

171956 is a deficient number, since it is larger than the sum of its proper divisors (128974).

171956 is a wasteful number, since it uses less digits than its factorization.

171956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42993 (or 42991 counting only the distinct ones).

The product of its digits is 1890, while the sum is 29.

The square root of 171956 is about 414.6757769632. The cubic root of 171956 is about 55.6082350689.

The spelling of 171956 in words is "one hundred seventy-one thousand, nine hundred fifty-six".