168381 has 12 divisors (see below), whose sum is σ = 248508. Its totient is φ = 109824.

The previous prime is 168353. The next prime is 168391. The reversal of 168381 is 183861.

It can be written as a sum of positive squares in 2 ways, for example, as 95481 + 72900 = 309^2 + 270^2 .

It is not a de Polignac number, because 168381 - 2⁷ = 168253 is a prime.

It is a super-2 number, since 2×168381² = 56704322322, which contains 22 as substring.

168381 is a lucky number.

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 168381.

It is not an unprimeable number, because it can be changed into a prime (168331) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 301 + ... + 653.

It is an arithmetic number, because the mean of its divisors is an integer number (20709).

2¹⁶⁸³⁸¹ is an apocalyptic number.

It is an amenable number.

168381 is a deficient number, since it is larger than the sum of its proper divisors (80127).

168381 is a wasteful number, since it uses less digits than its factorization.

168381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412 (or 409 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 168381 is about 410.3425398371. The cubic root of 168381 is about 55.2201643408.

It can be divided in two parts, 1683 and 81, that added together give a square (1764 = 42²).

The spelling of 168381 in words is "one hundred sixty-eight thousand, three hundred eighty-one".