181815941 has 2 divisors, whose sum is σ = 181815942. Its totient is φ = 181815940.

The previous prime is 181815937. The next prime is 181815971. The reversal of 181815941 is 149518181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 181467841 + 348100 = 13471^2 + 590^2 .

It is a cyclic number.

It is not a de Polignac number, because 181815941 - 2² = 181815937 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 181815895 and 181815904.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181815971) 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 as a sum of consecutive naturals, namely, 90907970 + 90907971.

It is an arithmetic number, because the mean of its divisors is an integer number (90907971).

Almost surely, 2^181815941 is an apocalyptic number.

It is an amenable number.

181815941 is a deficient number, since it is larger than the sum of its proper divisors (1).

181815941 is an equidigital number, since it uses as much as digits as its factorization.

181815941 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11520, while the sum is 38.

The square root of 181815941 is about 13483.9141572468. The cubic root of 181815941 is about 566.5140075896.

The spelling of 181815941 in words is "one hundred eighty-one million, eight hundred fifteen thousand, nine hundred forty-one".