81261560041291 has 16 divisors (see below), whose sum is σ = 93924316523520. Its totient is φ = 68862468692160.

The previous prime is 81261560041273. The next prime is 81261560041309. The reversal of 81261560041291 is 19214006516218.

It is an interprime number because it is at equal distance from previous prime (81261560041273) and next prime (81261560041309).

It is a cyclic number.

It is not a de Polignac number, because 81261560041291 - 2⁹ = 81261560040779 is a prime.

It is a super-2 number, since 2×81261560041291² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81261560041591) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1680931 + ... + 12858796.

It is an arithmetic number, because the mean of its divisors is an integer number (5870269782720).

Almost surely, 2^{81261560041291} is an apocalyptic number.

81261560041291 is a deficient number, since it is larger than the sum of its proper divisors (12662756482229).

81261560041291 is a wasteful number, since it uses less digits than its factorization.

81261560041291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14548794.

The product of its (nonzero) digits is 207360, while the sum is 46.

The spelling of 81261560041291 in words is "eighty-one trillion, two hundred sixty-one billion, five hundred sixty million, forty-one thousand, two hundred ninety-one".