181366 has 16 divisors (see below), whose sum is σ = 291600. Its totient is φ = 84448.

The previous prime is 181361. The next prime is 181387. The reversal of 181366 is 663181.

181366 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 181366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181361) by changing a digit.

181366 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3045 + ... + 3103.

It is an arithmetic number, because the mean of its divisors is an integer number (18225).

2¹⁸¹³⁶⁶ is an apocalyptic number.

181366 is a deficient number, since it is larger than the sum of its proper divisors (110234).

181366 is a wasteful number, since it uses less digits than its factorization.

181366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143.

The product of its digits is 864, while the sum is 25.

The square root of 181366 is about 425.8708724484. The cubic root of 181366 is about 56.6046303029.

The spelling of 181366 in words is "one hundred eighty-one thousand, three hundred sixty-six".