81678410897 has 2 divisors, whose sum is σ = 81678410898. Its totient is φ = 81678410896.

The previous prime is 81678410887. The next prime is 81678410899. The reversal of 81678410897 is 79801487618.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59083511041 + 22594899856 = 243071^2 + 150316^2 .

It is a cyclic number.

It is not a de Polignac number, because 81678410897 - 2⁶ = 81678410833 is a prime.

Together with 81678410899, 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 (81678410899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40839205448 + 40839205449.

It is an arithmetic number, because the mean of its divisors is an integer number (40839205449).

Almost surely, 2^81678410897 is an apocalyptic number.

It is an amenable number.

81678410897 is a deficient number, since it is larger than the sum of its proper divisors (1).

81678410897 is an equidigital number, since it uses as much as digits as its factorization.

81678410897 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5419008, while the sum is 59.

The spelling of 81678410897 in words is "eighty-one billion, six hundred seventy-eight million, four hundred ten thousand, eight hundred ninety-seven".