81006911723 has 2 divisors, whose sum is σ = 81006911724. Its totient is φ = 81006911722.

The previous prime is 81006911719. The next prime is 81006911737. The reversal of 81006911723 is 32711960018.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81006911723 - 2² = 81006911719 is a prime.

It is not a weakly prime, because it can be changed into another prime (81006611723) 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, 40503455861 + 40503455862.

It is an arithmetic number, because the mean of its divisors is an integer number (40503455862).

Almost surely, 2^81006911723 is an apocalyptic number.

81006911723 is a deficient number, since it is larger than the sum of its proper divisors (1).

81006911723 is an equidigital number, since it uses as much as digits as its factorization.

81006911723 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 38.

The spelling of 81006911723 in words is "eighty-one billion, six million, nine hundred eleven thousand, seven hundred twenty-three".