81697597123 has 2 divisors, whose sum is σ = 81697597124. Its totient is φ = 81697597122.

The previous prime is 81697597057. The next prime is 81697597133. The reversal of 81697597123 is 32179579618.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81697597123 is a prime.

It is not a weakly prime, because it can be changed into another prime (81697597133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40848798561 + 40848798562.

It is an arithmetic number, because the mean of its divisors is an integer number (40848798562).

Almost surely, 2^81697597123 is an apocalyptic number.

81697597123 is a deficient number, since it is larger than the sum of its proper divisors (1).

81697597123 is an equidigital number, since it uses as much as digits as its factorization.

81697597123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5715360, while the sum is 58.

The spelling of 81697597123 in words is "eighty-one billion, six hundred ninety-seven million, five hundred ninety-seven thousand, one hundred twenty-three".