81128541553 has 2 divisors, whose sum is σ = 81128541554. Its totient is φ = 81128541552.

The previous prime is 81128541517. The next prime is 81128541569. The reversal of 81128541553 is 35514582118.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80532791089 + 595750464 = 283783^2 + 24408^2 .

It is a cyclic number.

It is not a de Polignac number, because 81128541553 - 2¹³ = 81128533361 is a prime.

It is not a weakly prime, because it can be changed into another prime (81128571553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40564270776 + 40564270777.

It is an arithmetic number, because the mean of its divisors is an integer number (40564270777).

Almost surely, 2^81128541553 is an apocalyptic number.

It is an amenable number.

81128541553 is a deficient number, since it is larger than the sum of its proper divisors (1).

81128541553 is an equidigital number, since it uses as much as digits as its factorization.

81128541553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 192000, while the sum is 43.

The spelling of 81128541553 in words is "eighty-one billion, one hundred twenty-eight million, five hundred forty-one thousand, five hundred fifty-three".