181430681 has 4 divisors (see below), whose sum is σ = 192103092. Its totient is φ = 170758272.

The previous prime is 181430659. The next prime is 181430719. The reversal of 181430681 is 186034181.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186034181 = 593 ⋅313717.

It can be written as a sum of positive squares in 2 ways, for example, as 146797456 + 34633225 = 12116^2 + 5885^2 .

It is a cyclic number.

It is not a de Polignac number, because 181430681 - 2¹⁴ = 181414297 is a prime.

It is a super-2 number, since 2×181430681² = 65834184016247522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181430611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5336180 + ... + 5336213.

It is an arithmetic number, because the mean of its divisors is an integer number (48025773).

Almost surely, 2^181430681 is an apocalyptic number.

It is an amenable number.

181430681 is a deficient number, since it is larger than the sum of its proper divisors (10672411).

181430681 is a wasteful number, since it uses less digits than its factorization.

181430681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10672410.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 181430681 is about 13469.6206702342. The cubic root of 181430681 is about 566.1135851903.

The spelling of 181430681 in words is "one hundred eighty-one million, four hundred thirty thousand, six hundred eighty-one".