81342719 has 2 divisors, whose sum is σ = 81342720. Its totient is φ = 81342718.

The previous prime is 81342691. The next prime is 81342733. The reversal of 81342719 is 91724318.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81342719 is a prime.

It is a super-2 number, since 2×81342719² = 13233275868625922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81342119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40671359 + 40671360.

It is an arithmetic number, because the mean of its divisors is an integer number (40671360).

Almost surely, 2^81342719 is an apocalyptic number.

81342719 is a deficient number, since it is larger than the sum of its proper divisors (1).

81342719 is an equidigital number, since it uses as much as digits as its factorization.

81342719 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 35.

The square root of 81342719 is about 9019.0198469679. The cubic root of 81342719 is about 433.2842424994.

The spelling of 81342719 in words is "eighty-one million, three hundred forty-two thousand, seven hundred nineteen".