181981938 has 8 divisors (see below), whose sum is σ = 363963888. Its totient is φ = 60660644.

The previous prime is 181981937. The next prime is 181981939. The reversal of 181981938 is 839189181.

181981938 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (181981937) and next prime (181981939).

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

181981938 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (181981937) 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, 15165156 + ... + 15165167.

It is an arithmetic number, because the mean of its divisors is an integer number (45495486).

Almost surely, 2^181981938 is an apocalyptic number.

181981938 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

181981938 is a wasteful number, since it uses less digits than its factorization.

181981938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30330328.

The product of its digits is 124416, while the sum is 48.

The square root of 181981938 is about 13490.0681243647. The cubic root of 181981938 is about 566.6863632523.

The spelling of 181981938 in words is "one hundred eighty-one million, nine hundred eighty-one thousand, nine hundred thirty-eight".