181839641 has 2 divisors, whose sum is σ = 181839642. Its totient is φ = 181839640.

The previous prime is 181839629. The next prime is 181839643. The reversal of 181839641 is 146938181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 130416400 + 51423241 = 11420^2 + 7171^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-181839641 is a prime.

Together with 181839643, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (181839643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90919820 + 90919821.

It is an arithmetic number, because the mean of its divisors is an integer number (90919821).

Almost surely, 2^181839641 is an apocalyptic number.

It is an amenable number.

181839641 is a deficient number, since it is larger than the sum of its proper divisors (1).

181839641 is an equidigital number, since it uses as much as digits as its factorization.

181839641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 41.

The square root of 181839641 is about 13484.7929535459. The cubic root of 181839641 is about 566.5386218571.

The spelling of 181839641 in words is "one hundred eighty-one million, eight hundred thirty-nine thousand, six hundred forty-one".