181089481 has 2 divisors, whose sum is σ = 181089482. Its totient is φ = 181089480.

The previous prime is 181089479. The next prime is 181089521. The reversal of 181089481 is 184980181.

181089481 = 9515² + 9516².

181089481 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (181089521) can be obtained adding 181089481 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90554256 + 90535225 = 9516^2 + 9515^2 .

It is a cyclic number.

It is not a de Polignac number, because 181089481 - 2¹ = 181089479 is a prime.

It is a super-2 number, since 2×181089481² = 65586800257698722, which contains 22 as substring.

Together with 181089479, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (181089401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90544740 + 90544741.

It is an arithmetic number, because the mean of its divisors is an integer number (90544741).

Almost surely, 2^181089481 is an apocalyptic number.

181089481 is the 9516-th centered square number.

It is an amenable number.

181089481 is a deficient number, since it is larger than the sum of its proper divisors (1).

181089481 is an equidigital number, since it uses as much as digits as its factorization.

181089481 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18432, while the sum is 40.

The square root of 181089481 is about 13456.9491713389. The cubic root of 181089481 is about 565.7584832386.

The spelling of 181089481 in words is "one hundred eighty-one million, eighty-nine thousand, four hundred eighty-one".