81336808447 has 2 divisors, whose sum is σ = 81336808448. Its totient is φ = 81336808446.

The previous prime is 81336808433. The next prime is 81336808453. The reversal of 81336808447 is 74480863318.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81336808447 - 2¹¹ = 81336806399 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81336808394 and 81336808403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81336808417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40668404223 + 40668404224.

It is an arithmetic number, because the mean of its divisors is an integer number (40668404224).

Almost surely, 2^81336808447 is an apocalyptic number.

81336808447 is a deficient number, since it is larger than the sum of its proper divisors (1).

81336808447 is an equidigital number, since it uses as much as digits as its factorization.

81336808447 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3096576, while the sum is 52.

The spelling of 81336808447 in words is "eighty-one billion, three hundred thirty-six million, eight hundred eight thousand, four hundred forty-seven".