181297813 has 6 divisors (see below), whose sum is σ = 183515414. Its totient is φ = 179106696.

The previous prime is 181297807. The next prime is 181297849. The reversal of 181297813 is 318792181.

181297813 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., 163379524 + 17918289 = 12782^2 + 4233^2 .

It is not a de Polignac number, because 181297813 - 2⁹ = 181297301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181297873) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6270 + ... + 20047.

Almost surely, 2^181297813 is an apocalyptic number.

It is an amenable number.

181297813 is a deficient number, since it is larger than the sum of its proper divisors (2217601).

181297813 is an frugal number, since it uses more digits than its factorization.

181297813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26483 (or 26400 counting only the distinct ones).

The product of its digits is 24192, while the sum is 40.

The square root of 181297813 is about 13464.6876309850. The cubic root of 181297813 is about 565.9753565500.

The spelling of 181297813 in words is "one hundred eighty-one million, two hundred ninety-seven thousand, eight hundred thirteen".