81338384563 has 2 divisors, whose sum is σ = 81338384564. Its totient is φ = 81338384562.

The previous prime is 81338384539. The next prime is 81338384581. The reversal of 81338384563 is 36548383318.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81338384563 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81338384563.

It is not a weakly prime, because it can be changed into another prime (81338384593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40669192281 + 40669192282.

It is an arithmetic number, because the mean of its divisors is an integer number (40669192282).

Almost surely, 2^81338384563 is an apocalyptic number.

81338384563 is a deficient number, since it is larger than the sum of its proper divisors (1).

81338384563 is an equidigital number, since it uses as much as digits as its factorization.

81338384563 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4976640, while the sum is 52.

The spelling of 81338384563 in words is "eighty-one billion, three hundred thirty-eight million, three hundred eighty-four thousand, five hundred sixty-three".