81572189141089 has 2 divisors, whose sum is σ = 81572189141090. Its totient is φ = 81572189141088.

The previous prime is 81572189141041. The next prime is 81572189141099. The reversal of 81572189141089 is 98014198127518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64777273755489 + 16794915385600 = 8048433^2 + 4098160^2 .

It is a cyclic number.

It is not a de Polignac number, because 81572189141089 - 2³³ = 81563599206497 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81572189141089.

It is not a weakly prime, because it can be changed into another prime (81572189141099) 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, 40786094570544 + 40786094570545.

It is an arithmetic number, because the mean of its divisors is an integer number (40786094570545).

Almost surely, 2^{81572189141089} is an apocalyptic number.

It is an amenable number.

81572189141089 is a deficient number, since it is larger than the sum of its proper divisors (1).

81572189141089 is an equidigital number, since it uses as much as digits as its factorization.

81572189141089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11612160, while the sum is 64.

The spelling of 81572189141089 in words is "eighty-one trillion, five hundred seventy-two billion, one hundred eighty-nine million, one hundred forty-one thousand, eighty-nine".