81818069 has 2 divisors, whose sum is σ = 81818070. Its totient is φ = 81818068.

The previous prime is 81818003. The next prime is 81818111. The reversal of 81818069 is 96081818.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80317444 + 1500625 = 8962^2 + 1225^2 .

It is a cyclic number.

It is not a de Polignac number, because 81818069 - 2¹² = 81813973 is a prime.

It is a super-2 number, since 2×81818069² = 13388392829777522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81818969) 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, 40909034 + 40909035.

It is an arithmetic number, because the mean of its divisors is an integer number (40909035).

Almost surely, 2^81818069 is an apocalyptic number.

It is an amenable number.

81818069 is a deficient number, since it is larger than the sum of its proper divisors (1).

81818069 is an equidigital number, since it uses as much as digits as its factorization.

81818069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27648, while the sum is 41.

The square root of 81818069 is about 9045.3341010711. The cubic root of 81818069 is about 434.1266115340.

The spelling of 81818069 in words is "eighty-one million, eight hundred eighteen thousand, sixty-nine".