81208459 has 2 divisors, whose sum is σ = 81208460. Its totient is φ = 81208458.

The previous prime is 81208453. The next prime is 81208471. The reversal of 81208459 is 95480218.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81208459 - 2¹⁹ = 80684171 is a prime.

It is not a weakly prime, because it can be changed into another prime (81208453) 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, 40604229 + 40604230.

It is an arithmetic number, because the mean of its divisors is an integer number (40604230).

Almost surely, 2^81208459 is an apocalyptic number.

81208459 is a deficient number, since it is larger than the sum of its proper divisors (1).

81208459 is an equidigital number, since it uses as much as digits as its factorization.

81208459 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 81208459 is about 9011.5736139700. The cubic root of 81208459 is about 433.0457258539.

The spelling of 81208459 in words is "eighty-one million, two hundred eight thousand, four hundred fifty-nine".