81818179 has 2 divisors, whose sum is σ = 81818180. Its totient is φ = 81818178.

The previous prime is 81818173. The next prime is 81818197. The reversal of 81818179 is 97181818.

Together with next prime (81818197) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81818179 - 2⁵ = 81818147 is a prime.

It is not a weakly prime, because it can be changed into another prime (81818173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40909089 + 40909090.

It is an arithmetic number, because the mean of its divisors is an integer number (40909090).

Almost surely, 2^81818179 is an apocalyptic number.

81818179 is a deficient number, since it is larger than the sum of its proper divisors (1).

81818179 is an equidigital number, since it uses as much as digits as its factorization.

81818179 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32256, while the sum is 43.

The square root of 81818179 is about 9045.3401815520. The cubic root of 81818179 is about 434.1268060872.

The spelling of 81818179 in words is "eighty-one million, eight hundred eighteen thousand, one hundred seventy-nine".