81113771 has 2 divisors, whose sum is σ = 81113772. Its totient is φ = 81113770.

The previous prime is 81113761. The next prime is 81113779. The reversal of 81113771 is 17731118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81113771 - 2⁶ = 81113707 is a prime.

It is equal to p_4730762 and since 81113771 and 4730762 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (81113779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40556885 + 40556886.

It is an arithmetic number, because the mean of its divisors is an integer number (40556886).

Almost surely, 2^81113771 is an apocalyptic number.

81113771 is a deficient number, since it is larger than the sum of its proper divisors (1).

81113771 is an equidigital number, since it uses as much as digits as its factorization.

81113771 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1176, while the sum is 29.

The square root of 81113771 is about 9006.3183932171. The cubic root of 81113771 is about 432.8773518474.

Adding to 81113771 its reverse (17731118), we get a palindrome (98844889).

The spelling of 81113771 in words is "eighty-one million, one hundred thirteen thousand, seven hundred seventy-one".