81373002497 has 2 divisors, whose sum is σ = 81373002498. Its totient is φ = 81373002496.

The previous prime is 81373002439. The next prime is 81373002499. The reversal of 81373002497 is 79420037318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62045329921 + 19327672576 = 249089^2 + 139024^2 .

It is a cyclic number.

It is not a de Polignac number, because 81373002497 - 2¹² = 81372998401 is a prime.

Together with 81373002499, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81373002499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40686501248 + 40686501249.

It is an arithmetic number, because the mean of its divisors is an integer number (40686501249).

Almost surely, 2^81373002497 is an apocalyptic number.

It is an amenable number.

81373002497 is a deficient number, since it is larger than the sum of its proper divisors (1).

81373002497 is an equidigital number, since it uses as much as digits as its factorization.

81373002497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 254016, while the sum is 44.

The spelling of 81373002497 in words is "eighty-one billion, three hundred seventy-three million, two thousand, four hundred ninety-seven".