168981 has 16 divisors (see below), whose sum is σ = 245760. Its totient is φ = 102960.

The previous prime is 168977. The next prime is 168991. The reversal of 168981 is 189861.

168981 = 133² + 134² + ... + 141².

It is not a de Polignac number, because 168981 - 2² = 168977 is a prime.

It is a super-2 number, since 2×168981² = 57109156722, which contains 22 as substring.

It is a zygodrome in base 4.

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 168981.

It is not an unprimeable number, because it can be changed into a prime (168901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2100 + ... + 2178.

It is an arithmetic number, because the mean of its divisors is an integer number (15360).

2¹⁶⁸⁹⁸¹ is an apocalyptic number.

It is an amenable number.

168981 is a deficient number, since it is larger than the sum of its proper divisors (76779).

168981 is a wasteful number, since it uses less digits than its factorization.

168981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136.

The product of its digits is 3456, while the sum is 33.

The square root of 168981 is about 411.0729862202. The cubic root of 168981 is about 55.2856761317.

It can be divided in two parts, 1689 and 81, that added together give a triangular number (1770 = T₅₉).

The spelling of 168981 in words is "one hundred sixty-eight thousand, nine hundred eighty-one".