81837079 has 2 divisors, whose sum is σ = 81837080. Its totient is φ = 81837078.

The previous prime is 81837053. The next prime is 81837097. The reversal of 81837079 is 97073818.

Together with next prime (81837097) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81837079 - 2¹¹ = 81835031 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81837479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40918539 + 40918540.

It is an arithmetic number, because the mean of its divisors is an integer number (40918540).

Almost surely, 2^81837079 is an apocalyptic number.

81837079 is a deficient number, since it is larger than the sum of its proper divisors (1).

81837079 is an equidigital number, since it uses as much as digits as its factorization.

81837079 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84672, while the sum is 43.

The square root of 81837079 is about 9046.3848580524. The cubic root of 81837079 is about 434.1602312788.

The spelling of 81837079 in words is "eighty-one million, eight hundred thirty-seven thousand, seventy-nine".