81958247719 has 2 divisors, whose sum is σ = 81958247720. Its totient is φ = 81958247718.

The previous prime is 81958247687. The next prime is 81958247731. The reversal of 81958247719 is 91774285918.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81958247719 - 2⁵ = 81958247687 is a prime.

It is a super-2 number, since 2×81958247719² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81958247519) 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, 40979123859 + 40979123860.

It is an arithmetic number, because the mean of its divisors is an integer number (40979123860).

Almost surely, 2^81958247719 is an apocalyptic number.

81958247719 is a deficient number, since it is larger than the sum of its proper divisors (1).

81958247719 is an equidigital number, since it uses as much as digits as its factorization.

81958247719 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10160640, while the sum is 61.

The spelling of 81958247719 in words is "eighty-one billion, nine hundred fifty-eight million, two hundred forty-seven thousand, seven hundred nineteen".