181791289 has 9 divisors (see below), whose sum is σ = 185015727. Its totient is φ = 178622784.

The previous prime is 181791283. The next prime is 181791293. The reversal of 181791289 is 982197181.

The square root of 181791289 is 13483.

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

It can be written as a sum of positive squares in only one way, i.e., 81631225 + 100160064 = 9035^2 + 10008^2 .

It is not a de Polignac number, because 181791289 - 2⁵ = 181791257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181791283) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1307782 + ... + 1307920.

It is an arithmetic number, because the mean of its divisors is an integer number (20557303).

Almost surely, 2^181791289 is an apocalyptic number.

181791289 is the 13483-rd square number.

181791289 is the 6742-nd centered octagonal number.

It is an amenable number.

181791289 is a deficient number, since it is larger than the sum of its proper divisors (3224438).

181791289 is an frugal number, since it uses more digits than its factorization.

181791289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472 (or 236 counting only the distinct ones).

The product of its digits is 72576, while the sum is 46.

The cubic root of 181791289 is about 566.4884023274.

The spelling of 181791289 in words is "one hundred eighty-one million, seven hundred ninety-one thousand, two hundred eighty-nine".