181144681 has 9 divisors (see below), whose sum is σ = 186049719. Its totient is φ = 176366736.

The previous prime is 181144679. The next prime is 181144699. The reversal of 181144681 is 186441181.

The square root of 181144681 is 13459.

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., 1155625 + 179989056 = 1075^2 + 13416^2 .

It is not a de Polignac number, because 181144681 - 2¹ = 181144679 is a prime.

It is a super-2 number, since 2×181144681² = 65626790909183522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181144631) 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, 578581 + ... + 578893.

It is an arithmetic number, because the mean of its divisors is an integer number (20672191).

Almost surely, 2^181144681 is an apocalyptic number.

181144681 is the 13459-th square number.

181144681 is the 6730-th centered octagonal number.

It is an amenable number.

181144681 is a deficient number, since it is larger than the sum of its proper divisors (4905038).

181144681 is an frugal number, since it uses more digits than its factorization.

181144681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 712 (or 356 counting only the distinct ones).

The product of its digits is 6144, while the sum is 34.

The cubic root of 181144681 is about 565.8159625493.

The spelling of 181144681 in words is "one hundred eighty-one million, one hundred forty-four thousand, six hundred eighty-one".