170981 has 4 divisors (see below), whose sum is σ = 180000. Its totient is φ = 161964.

The previous prime is 170971. The next prime is 171007. The reversal of 170981 is 189071.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 189071 = 43 ⋅4397.

It is a cyclic number.

It is not a de Polignac number, because 170981 - 2¹⁰ = 169957 is a prime.

It is a super-3 number, since 3×170981³ = 14995633344558423, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 170981.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 170981.

It is not an unprimeable number, because it can be changed into a prime (170921) 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 in 3 ways as a sum of consecutive naturals, for example, 4481 + ... + 4518.

It is an arithmetic number, because the mean of its divisors is an integer number (45000).

2¹⁷⁰⁹⁸¹ is an apocalyptic number.

It is an amenable number.

170981 is a deficient number, since it is larger than the sum of its proper divisors (9019).

170981 is an equidigital number, since it uses as much as digits as its factorization.

170981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9018.

The product of its (nonzero) digits is 504, while the sum is 26.

The square root of 170981 is about 413.4984885099. The cubic root of 170981 is about 55.5029352126.

The spelling of 170981 in words is "one hundred seventy thousand, nine hundred eighty-one".