81481708723 has 2 divisors, whose sum is σ = 81481708724. Its totient is φ = 81481708722.

The previous prime is 81481708687. The next prime is 81481708733. The reversal of 81481708723 is 32780718418.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81481708723 - 2⁹ = 81481708211 is a prime.

It is not a weakly prime, because it can be changed into another prime (81481708733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40740854361 + 40740854362.

It is an arithmetic number, because the mean of its divisors is an integer number (40740854362).

Almost surely, 2^81481708723 is an apocalyptic number.

81481708723 is a deficient number, since it is larger than the sum of its proper divisors (1).

81481708723 is an equidigital number, since it uses as much as digits as its factorization.

81481708723 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 602112, while the sum is 49.

The spelling of 81481708723 in words is "eighty-one billion, four hundred eighty-one million, seven hundred eight thousand, seven hundred twenty-three".