81058217 has 2 divisors, whose sum is σ = 81058218. Its totient is φ = 81058216.

The previous prime is 81058207. The next prime is 81058247. The reversal of 81058217 is 71285018.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71503936 + 9554281 = 8456^2 + 3091^2 .

It is a cyclic number.

It is not a de Polignac number, because 81058217 - 2⁸ = 81057961 is a prime.

It is not a weakly prime, because it can be changed into another prime (81058207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40529108 + 40529109.

It is an arithmetic number, because the mean of its divisors is an integer number (40529109).

Almost surely, 2^81058217 is an apocalyptic number.

It is an amenable number.

81058217 is a deficient number, since it is larger than the sum of its proper divisors (1).

81058217 is an equidigital number, since it uses as much as digits as its factorization.

81058217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 81058217 is about 9003.2336968447. The cubic root of 81058217 is about 432.7785048399.

The spelling of 81058217 in words is "eighty-one million, fifty-eight thousand, two hundred seventeen".