81871767611 has 2 divisors, whose sum is σ = 81871767612. Its totient is φ = 81871767610.

The previous prime is 81871767569. The next prime is 81871767623. The reversal of 81871767611 is 11676717818.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81871767611 is a prime.

It is not a weakly prime, because it can be changed into another prime (81871727611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40935883805 + 40935883806.

It is an arithmetic number, because the mean of its divisors is an integer number (40935883806).

Almost surely, 2^81871767611 is an apocalyptic number.

81871767611 is a deficient number, since it is larger than the sum of its proper divisors (1).

81871767611 is an equidigital number, since it uses as much as digits as its factorization.

81871767611 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 790272, while the sum is 53.

The spelling of 81871767611 in words is "eighty-one billion, eight hundred seventy-one million, seven hundred sixty-seven thousand, six hundred eleven".