81471426497 has 2 divisors, whose sum is σ = 81471426498. Its totient is φ = 81471426496.

The previous prime is 81471426479. The next prime is 81471426511. The reversal of 81471426497 is 79462417418.

Together with previous prime (81471426479) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75273958321 + 6197468176 = 274361^2 + 78724^2 .

It is a cyclic number.

It is not a de Polignac number, because 81471426497 - 2⁸ = 81471426241 is a prime.

It is not a weakly prime, because it can be changed into another prime (81471423497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40735713248 + 40735713249.

It is an arithmetic number, because the mean of its divisors is an integer number (40735713249).

Almost surely, 2^81471426497 is an apocalyptic number.

It is an amenable number.

81471426497 is a deficient number, since it is larger than the sum of its proper divisors (1).

81471426497 is an equidigital number, since it uses as much as digits as its factorization.

81471426497 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2709504, while the sum is 53.

The spelling of 81471426497 in words is "eighty-one billion, four hundred seventy-one million, four hundred twenty-six thousand, four hundred ninety-seven".