81059180641 has 2 divisors, whose sum is σ = 81059180642. Its totient is φ = 81059180640.

The previous prime is 81059180627. The next prime is 81059180677. The reversal of 81059180641 is 14608195018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70121158416 + 10938022225 = 264804^2 + 104585^2 .

It is a cyclic number.

It is not a de Polignac number, because 81059180641 - 2¹³ = 81059172449 is a prime.

It is not a weakly prime, because it can be changed into another prime (81059180941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40529590320 + 40529590321.

It is an arithmetic number, because the mean of its divisors is an integer number (40529590321).

Almost surely, 2^81059180641 is an apocalyptic number.

It is an amenable number.

81059180641 is a deficient number, since it is larger than the sum of its proper divisors (1).

81059180641 is an equidigital number, since it uses as much as digits as its factorization.

81059180641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69120, while the sum is 43.

The spelling of 81059180641 in words is "eighty-one billion, fifty-nine million, one hundred eighty thousand, six hundred forty-one".