81122771911 has 2 divisors, whose sum is σ = 81122771912. Its totient is φ = 81122771910.

The previous prime is 81122771833. The next prime is 81122771923. The reversal of 81122771911 is 11917722118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81122771911 - 2¹³ = 81122763719 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81122781911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40561385955 + 40561385956.

It is an arithmetic number, because the mean of its divisors is an integer number (40561385956).

Almost surely, 2^81122771911 is an apocalyptic number.

81122771911 is a deficient number, since it is larger than the sum of its proper divisors (1).

81122771911 is an equidigital number, since it uses as much as digits as its factorization.

81122771911 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14112, while the sum is 40.

The spelling of 81122771911 in words is "eighty-one billion, one hundred twenty-two million, seven hundred seventy-one thousand, nine hundred eleven".