181997361 has 40 divisors (see below), whose sum is σ = 334625984. Its totient is φ = 95994720.

The previous prime is 181997357. The next prime is 181997369. The reversal of 181997361 is 163799181.

181997361 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 181997361 - 2² = 181997357 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (181997369) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4975 + ... + 19716.

Almost surely, 2^181997361 is an apocalyptic number.

It is an amenable number.

181997361 is a deficient number, since it is larger than the sum of its proper divisors (152628623).

181997361 is a wasteful number, since it uses less digits than its factorization.

181997361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24723 (or 24714 counting only the distinct ones).

The product of its digits is 81648, while the sum is 45.

The square root of 181997361 is about 13490.6397550302. The cubic root of 181997361 is about 566.7023717218.

The spelling of 181997361 in words is "one hundred eighty-one million, nine hundred ninety-seven thousand, three hundred sixty-one".