81481171 has 2 divisors, whose sum is σ = 81481172. Its totient is φ = 81481170.

The previous prime is 81481159. The next prime is 81481181. The reversal of 81481171 is 17118418.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81481171 - 2¹⁷ = 81350099 is a prime.

It is a plaindrome in base 12.

It is not a weakly prime, because it can be changed into another prime (81481151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40740585 + 40740586.

It is an arithmetic number, because the mean of its divisors is an integer number (40740586).

Almost surely, 2^81481171 is an apocalyptic number.

81481171 is a deficient number, since it is larger than the sum of its proper divisors (1).

81481171 is an equidigital number, since it uses as much as digits as its factorization.

81481171 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1792, while the sum is 31.

The square root of 81481171 is about 9026.6921405352. The cubic root of 81481171 is about 433.5299316337.

Adding to 81481171 its reverse (17118418), we get a palindrome (98599589).

The spelling of 81481171 in words is "eighty-one million, four hundred eighty-one thousand, one hundred seventy-one".