81366193 has 2 divisors, whose sum is σ = 81366194. Its totient is φ = 81366192.

The previous prime is 81366169. The next prime is 81366217. The reversal of 81366193 is 39166318.

It is a balanced prime because it is at equal distance from previous prime (81366169) and next prime (81366217).

It can be written as a sum of positive squares in only one way, i.e., 71774784 + 9591409 = 8472^2 + 3097^2 .

It is a cyclic number.

It is not a de Polignac number, because 81366193 - 2⁵ = 81366161 is a prime.

It is not a weakly prime, because it can be changed into another prime (81361193) 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, 40683096 + 40683097.

It is an arithmetic number, because the mean of its divisors is an integer number (40683097).

Almost surely, 2^81366193 is an apocalyptic number.

It is an amenable number.

81366193 is a deficient number, since it is larger than the sum of its proper divisors (1).

81366193 is an equidigital number, since it uses as much as digits as its factorization.

81366193 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 37.

The square root of 81366193 is about 9020.3211140181. The cubic root of 81366193 is about 433.3259177561.

The spelling of 81366193 in words is "eighty-one million, three hundred sixty-six thousand, one hundred ninety-three".