81527744897 has 2 divisors, whose sum is σ = 81527744898. Its totient is φ = 81527744896.

The previous prime is 81527744891. The next prime is 81527744911. The reversal of 81527744897 is 79844772518.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62735721841 + 18792023056 = 250471^2 + 137084^2 .

It is a cyclic number.

It is not a de Polignac number, because 81527744897 - 2¹⁶ = 81527679361 is a prime.

It is not a weakly prime, because it can be changed into another prime (81527744891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40763872448 + 40763872449.

It is an arithmetic number, because the mean of its divisors is an integer number (40763872449).

Almost surely, 2^81527744897 is an apocalyptic number.

It is an amenable number.

81527744897 is a deficient number, since it is larger than the sum of its proper divisors (1).

81527744897 is an equidigital number, since it uses as much as digits as its factorization.

81527744897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31610880, while the sum is 62.

The spelling of 81527744897 in words is "eighty-one billion, five hundred twenty-seven million, seven hundred forty-four thousand, eight hundred ninety-seven".