81229275073 has 2 divisors, whose sum is σ = 81229275074. Its totient is φ = 81229275072.

The previous prime is 81229275031. The next prime is 81229275119. The reversal of 81229275073 is 37057292218.

It is an a-pointer prime, because the next prime (81229275119) can be obtained adding 81229275073 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46745899264 + 34483375809 = 216208^2 + 185697^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81229275073 is a prime.

It is not a weakly prime, because it can be changed into another prime (81229279073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40614637536 + 40614637537.

It is an arithmetic number, because the mean of its divisors is an integer number (40614637537).

Almost surely, 2^81229275073 is an apocalyptic number.

It is an amenable number.

81229275073 is a deficient number, since it is larger than the sum of its proper divisors (1).

81229275073 is an equidigital number, since it uses as much as digits as its factorization.

81229275073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 423360, while the sum is 46.

The spelling of 81229275073 in words is "eighty-one billion, two hundred twenty-nine million, two hundred seventy-five thousand, seventy-three".