181906 has 8 divisors (see below), whose sum is σ = 287280. Its totient is φ = 86148.

The previous prime is 181903. The next prime is 181913. The reversal of 181906 is 609181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an Ulam number.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (181903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2356 + ... + 2431.

It is an arithmetic number, because the mean of its divisors is an integer number (35910).

2¹⁸¹⁹⁰⁶ is an apocalyptic number.

181906 is a deficient number, since it is larger than the sum of its proper divisors (105374).

181906 is a wasteful number, since it uses less digits than its factorization.

181906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4808.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 181906 is about 426.5043962259. The cubic root of 181906 is about 56.6607529392.

The spelling of 181906 in words is "one hundred eighty-one thousand, nine hundred six".