81306271 has 2 divisors, whose sum is σ = 81306272. Its totient is φ = 81306270.

The previous prime is 81306259. The next prime is 81306299. The reversal of 81306271 is 17260318.

It is an a-pointer prime, because the next prime (81306299) can be obtained adding 81306271 to its sum of digits (28).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81306271 is a prime.

It is a super-2 number, since 2×81306271² = 13221419407850882, which contains 22 as substring.

It is equal to p_4741318 and since 81306271 and 4741318 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81306571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40653135 + 40653136.

It is an arithmetic number, because the mean of its divisors is an integer number (40653136).

Almost surely, 2^81306271 is an apocalyptic number.

81306271 is a deficient number, since it is larger than the sum of its proper divisors (1).

81306271 is an equidigital number, since it uses as much as digits as its factorization.

81306271 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 81306271 is about 9016.9990018853. Note that the first 3 decimals coincide. The cubic root of 81306271 is about 433.2195175775.

Adding to 81306271 its reverse (17260318), we get a palindrome (98566589).

The spelling of 81306271 in words is "eighty-one million, three hundred six thousand, two hundred seventy-one".