181805442 has 64 divisors (see below), whose sum is σ = 449137920. Its totient is φ = 47775744.

The previous prime is 181805431. The next prime is 181805443. The reversal of 181805442 is 244508181.

It is not an unprimeable number, because it can be changed into a prime (181805443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 236034 + ... + 236802.

It is an arithmetic number, because the mean of its divisors is an integer number (7017780).

Almost surely, 2^181805442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 181805442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224568960).

181805442 is an abundant number, since it is smaller than the sum of its proper divisors (267332478).

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

181805442 is a wasteful number, since it uses less digits than its factorization.

181805442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1227.

The product of its (nonzero) digits is 10240, while the sum is 33.

The square root of 181805442 is about 13483.5248358877. The cubic root of 181805442 is about 566.5031028893.

The spelling of 181805442 in words is "one hundred eighty-one million, eight hundred five thousand, four hundred forty-two".