81041688029 has 2 divisors, whose sum is σ = 81041688030. Its totient is φ = 81041688028.

The previous prime is 81041687977. The next prime is 81041688037. The reversal of 81041688029 is 92088614018.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49416400804 + 31625287225 = 222298^2 + 177835^2 .

It is a cyclic number.

It is not a de Polignac number, because 81041688029 - 2³² = 76746720733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81041688529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40520844014 + 40520844015.

It is an arithmetic number, because the mean of its divisors is an integer number (40520844015).

Almost surely, 2^81041688029 is an apocalyptic number.

It is an amenable number.

81041688029 is a deficient number, since it is larger than the sum of its proper divisors (1).

81041688029 is an equidigital number, since it uses as much as digits as its factorization.

81041688029 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 221184, while the sum is 47.

The spelling of 81041688029 in words is "eighty-one billion, forty-one million, six hundred eighty-eight thousand, twenty-nine".