181144723321 has 9 divisors (see below), whose sum is σ = 186189031791. Its totient is φ = 176233597992.

The previous prime is 181144723307. The next prime is 181144723349. The reversal of 181144723321 is 123327441181.

The square root of 181144723321 is 425611.

It is a perfect power (a square), and thus also a powerful number.

181144723321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 162090786025 + 19053937296 = 402605^2 + 138036^2 .

It is not a de Polignac number, because 181144723321 - 2¹⁷ = 181144592249 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181144723381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 15741856 + ... + 15753358.

It is an arithmetic number, because the mean of its divisors is an integer number (20687670199).

Almost surely, 2^181144723321 is an apocalyptic number.

181144723321 is the 425611-st square number.

181144723321 is the 212806-th centered octagonal number.

It is an amenable number.

181144723321 is a deficient number, since it is larger than the sum of its proper divisors (5044308470).

181144723321 is an frugal number, since it uses more digits than its factorization.

181144723321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23080 (or 11540 counting only the distinct ones).

The product of its digits is 32256, while the sum is 37.

The spelling of 181144723321 in words is "one hundred eighty-one billion, one hundred forty-four million, seven hundred twenty-three thousand, three hundred twenty-one".