181636 has 24 divisors (see below), whose sum is σ = 392000. Its totient is φ = 71712.

The previous prime is 181619. The next prime is 181639. The reversal of 181636 is 636181.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 181636.

It is not an unprimeable number, because it can be changed into a prime (181639) 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 7 ways as a sum of consecutive naturals, for example, 115 + ... + 613.

2¹⁸¹⁶³⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 181636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (196000).

181636 is an abundant number, since it is smaller than the sum of its proper divisors (210364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

181636 is a wasteful number, since it uses less digits than its factorization.

181636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 523 (or 521 counting only the distinct ones).

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

The square root of 181636 is about 426.1877520530. The cubic root of 181636 is about 56.6327055253.

The spelling of 181636 in words is "one hundred eighty-one thousand, six hundred thirty-six".