81422897 has 2 divisors, whose sum is σ = 81422898. Its totient is φ = 81422896.

The previous prime is 81422863. The next prime is 81422899. The reversal of 81422897 is 79822418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80982001 + 440896 = 8999^2 + 664^2 .

It is a cyclic number.

It is not a de Polignac number, because 81422897 - 2¹⁸ = 81160753 is a prime.

Together with 81422899, 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 (81422899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40711448 + 40711449.

It is an arithmetic number, because the mean of its divisors is an integer number (40711449).

Almost surely, 2^81422897 is an apocalyptic number.

It is an amenable number.

81422897 is a deficient number, since it is larger than the sum of its proper divisors (1).

81422897 is an equidigital number, since it uses as much as digits as its factorization.

81422897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64512, while the sum is 41.

The square root of 81422897 is about 9023.4636919533. The cubic root of 81422897 is about 433.4265558149.

The spelling of 81422897 in words is "eighty-one million, four hundred twenty-two thousand, eight hundred ninety-seven".