81548328289 has 2 divisors, whose sum is σ = 81548328290. Its totient is φ = 81548328288.

The previous prime is 81548328283. The next prime is 81548328311. The reversal of 81548328289 is 98282384518.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79490163600 + 2058164689 = 281940^2 + 45367^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81548328289 is a prime.

It is not a weakly prime, because it can be changed into another prime (81548328283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40774164144 + 40774164145.

It is an arithmetic number, because the mean of its divisors is an integer number (40774164145).

Almost surely, 2^81548328289 is an apocalyptic number.

It is an amenable number.

81548328289 is a deficient number, since it is larger than the sum of its proper divisors (1).

81548328289 is an equidigital number, since it uses as much as digits as its factorization.

81548328289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8847360, while the sum is 58.

The spelling of 81548328289 in words is "eighty-one billion, five hundred forty-eight million, three hundred twenty-eight thousand, two hundred eighty-nine".