81261560041273 has 2 divisors, whose sum is σ = 81261560041274. Its totient is φ = 81261560041272.

The previous prime is 81261560041267. The next prime is 81261560041309. The reversal of 81261560041273 is 37214006516218.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56015839203129 + 25245720838144 = 7484373^2 + 5024512^2 .

It is a cyclic number.

It is not a de Polignac number, because 81261560041273 - 2²⁵ = 81261526486841 is a prime.

It is a super-2 number, since 2×81261560041273² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81261560041223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40630780020636 + 40630780020637.

It is an arithmetic number, because the mean of its divisors is an integer number (40630780020637).

Almost surely, 2^{81261560041273} is an apocalyptic number.

It is an amenable number.

81261560041273 is a deficient number, since it is larger than the sum of its proper divisors (1).

81261560041273 is an equidigital number, since it uses as much as digits as its factorization.

81261560041273 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 483840, while the sum is 46.

The spelling of 81261560041273 in words is "eighty-one trillion, two hundred sixty-one billion, five hundred sixty million, forty-one thousand, two hundred seventy-three".