181000681 has 2 divisors, whose sum is σ = 181000682. Its totient is φ = 181000680.

The previous prime is 181000679. The next prime is 181000693. The reversal of 181000681 is 186000181.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 101505625 + 79495056 = 10075^2 + 8916^2 .

It is a cyclic number.

It is not a de Polignac number, because 181000681 - 2¹ = 181000679 is a prime.

It is a super-2 number, since 2×181000681² = 65522493044927522, which contains 22 as substring.

Together with 181000679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (181000601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90500340 + 90500341.

It is an arithmetic number, because the mean of its divisors is an integer number (90500341).

Almost surely, 2^181000681 is an apocalyptic number.

It is an amenable number.

181000681 is a deficient number, since it is larger than the sum of its proper divisors (1).

181000681 is an equidigital number, since it uses as much as digits as its factorization.

181000681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 25.

The square root of 181000681 is about 13453.6493562156. The cubic root of 181000681 is about 565.6659920069.

The spelling of 181000681 in words is "one hundred eighty-one million, six hundred eighty-one", and thus it is an aban number.