81238229 has 2 divisors, whose sum is σ = 81238230. Its totient is φ = 81238228.

The previous prime is 81238163. The next prime is 81238247. The reversal of 81238229 is 92283218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77035729 + 4202500 = 8777^2 + 2050^2 .

It is a cyclic number.

It is not a de Polignac number, because 81238229 - 2⁸ = 81237973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81238279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40619114 + 40619115.

It is an arithmetic number, because the mean of its divisors is an integer number (40619115).

Almost surely, 2^81238229 is an apocalyptic number.

It is an amenable number.

81238229 is a deficient number, since it is larger than the sum of its proper divisors (1).

81238229 is an equidigital number, since it uses as much as digits as its factorization.

81238229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 35.

The square root of 81238229 is about 9013.2252274089. The cubic root of 81238229 is about 433.0986357618.

The spelling of 81238229 in words is "eighty-one million, two hundred thirty-eight thousand, two hundred twenty-nine".