81400171 has 2 divisors, whose sum is σ = 81400172. Its totient is φ = 81400170.

The previous prime is 81400093. The next prime is 81400217. The reversal of 81400171 is 17100418.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81400171 - 2¹¹ = 81398123 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81400271) 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, 40700085 + 40700086.

It is an arithmetic number, because the mean of its divisors is an integer number (40700086).

Almost surely, 2^81400171 is an apocalyptic number.

81400171 is a deficient number, since it is larger than the sum of its proper divisors (1).

81400171 is an equidigital number, since it uses as much as digits as its factorization.

81400171 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 224, while the sum is 22.

The square root of 81400171 is about 9022.2043315367. The cubic root of 81400171 is about 433.3862274026.

Adding to 81400171 its reverse (17100418), we get a palindrome (98500589).

The spelling of 81400171 in words is "eighty-one million, four hundred thousand, one hundred seventy-one".