821345897 has 2 divisors, whose sum is σ = 821345898. Its totient is φ = 821345896.

The previous prime is 821345887. The next prime is 821345911. The reversal of 821345897 is 798543128.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 660284416 + 161061481 = 25696^2 + 12691^2 .

It is a cyclic number.

It is not a de Polignac number, because 821345897 - 2¹⁴ = 821329513 is a prime.

It is not a weakly prime, because it can be changed into another prime (821345887) 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, 410672948 + 410672949.

It is an arithmetic number, because the mean of its divisors is an integer number (410672949).

Almost surely, 2^821345897 is an apocalyptic number.

It is an amenable number.

821345897 is a deficient number, since it is larger than the sum of its proper divisors (1).

821345897 is an equidigital number, since it uses as much as digits as its factorization.

821345897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 483840, while the sum is 47.

The square root of 821345897 is about 28659.1328724370. The cubic root of 821345897 is about 936.5019744101.

The spelling of 821345897 in words is "eight hundred twenty-one million, three hundred forty-five thousand, eight hundred ninety-seven".