81404310497 has 2 divisors, whose sum is σ = 81404310498. Its totient is φ = 81404310496.

The previous prime is 81404310451. The next prime is 81404310499. The reversal of 81404310497 is 79401340418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81261484096 + 142826401 = 285064^2 + 11951^2 .

It is a cyclic number.

It is not a de Polignac number, because 81404310497 - 2³⁶ = 12684833761 is a prime.

Together with 81404310499, 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 (81404310499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40702155248 + 40702155249.

It is an arithmetic number, because the mean of its divisors is an integer number (40702155249).

Almost surely, 2^81404310497 is an apocalyptic number.

It is an amenable number.

81404310497 is a deficient number, since it is larger than the sum of its proper divisors (1).

81404310497 is an equidigital number, since it uses as much as digits as its factorization.

81404310497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96768, while the sum is 41.

The spelling of 81404310497 in words is "eighty-one billion, four hundred four million, three hundred ten thousand, four hundred ninety-seven".