820865447 has 2 divisors, whose sum is σ = 820865448. Its totient is φ = 820865446.

The previous prime is 820865411. The next prime is 820865483. The reversal of 820865447 is 744568028.

It is a balanced prime because it is at equal distance from previous prime (820865411) and next prime (820865483).

It is a cyclic number.

It is not a de Polignac number, because 820865447 - 2⁸ = 820865191 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 820865398 and 820865407.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (820865497) 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, 410432723 + 410432724.

It is an arithmetic number, because the mean of its divisors is an integer number (410432724).

Almost surely, 2^820865447 is an apocalyptic number.

820865447 is a deficient number, since it is larger than the sum of its proper divisors (1).

820865447 is an equidigital number, since it uses as much as digits as its factorization.

820865447 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 430080, while the sum is 44.

The square root of 820865447 is about 28650.7495015401. The cubic root of 820865447 is about 936.3193351040.

The spelling of 820865447 in words is "eight hundred twenty million, eight hundred sixty-five thousand, four hundred forty-seven".