81158417 has 2 divisors, whose sum is σ = 81158418. Its totient is φ = 81158416.

The previous prime is 81158401. The next prime is 81158431. The reversal of 81158417 is 71485118.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46771921 + 34386496 = 6839^2 + 5864^2 .

It is a cyclic number.

It is not a de Polignac number, because 81158417 - 2⁴ = 81158401 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81158447) 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, 40579208 + 40579209.

It is an arithmetic number, because the mean of its divisors is an integer number (40579209).

Almost surely, 2^81158417 is an apocalyptic number.

It is an amenable number.

81158417 is a deficient number, since it is larger than the sum of its proper divisors (1).

81158417 is an equidigital number, since it uses as much as digits as its factorization.

81158417 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8960, while the sum is 35.

The square root of 81158417 is about 9008.7966455016. The cubic root of 81158417 is about 432.9567575895.

The spelling of 81158417 in words is "eighty-one million, one hundred fifty-eight thousand, four hundred seventeen".