81343679 has 2 divisors, whose sum is σ = 81343680. Its totient is φ = 81343678.

The previous prime is 81343673. The next prime is 81343697. The reversal of 81343679 is 97634318.

Together with next prime (81343697) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81343679 is a prime.

It is a super-2 number, since 2×81343679² = 13233588226510082, 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 (81343673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40671839 + 40671840.

It is an arithmetic number, because the mean of its divisors is an integer number (40671840).

Almost surely, 2^81343679 is an apocalyptic number.

81343679 is a deficient number, since it is larger than the sum of its proper divisors (1).

81343679 is an equidigital number, since it uses as much as digits as its factorization.

81343679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 41.

The square root of 81343679 is about 9019.0730676716. The cubic root of 81343679 is about 433.2859470209.

The spelling of 81343679 in words is "eighty-one million, three hundred forty-three thousand, six hundred seventy-nine".