81066047801 has 2 divisors, whose sum is σ = 81066047802. Its totient is φ = 81066047800.

The previous prime is 81066047723. The next prime is 81066047851. The reversal of 81066047801 is 10874066018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77340166201 + 3725881600 = 278101^2 + 61040^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81066047801 is a prime.

It is not a weakly prime, because it can be changed into another prime (81066047851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40533023900 + 40533023901.

It is an arithmetic number, because the mean of its divisors is an integer number (40533023901).

Almost surely, 2^81066047801 is an apocalyptic number.

It is an amenable number.

81066047801 is a deficient number, since it is larger than the sum of its proper divisors (1).

81066047801 is an equidigital number, since it uses as much as digits as its factorization.

81066047801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64512, while the sum is 41.

The spelling of 81066047801 in words is "eighty-one billion, sixty-six million, forty-seven thousand, eight hundred one".