820567217 has 2 divisors, whose sum is σ = 820567218. Its totient is φ = 820567216.

The previous prime is 820567211. The next prime is 820567243. The reversal of 820567217 is 712765028.

820567217 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 469979041 + 350588176 = 21679^2 + 18724^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-820567217 is a prime.

It is not a weakly prime, because it can be changed into another prime (820567211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410283608 + 410283609.

It is an arithmetic number, because the mean of its divisors is an integer number (410283609).

Almost surely, 2^820567217 is an apocalyptic number.

It is an amenable number.

820567217 is a deficient number, since it is larger than the sum of its proper divisors (1).

820567217 is an equidigital number, since it uses as much as digits as its factorization.

820567217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 47040, while the sum is 38.

The square root of 820567217 is about 28645.5444528464. The cubic root of 820567217 is about 936.2059294539.

The spelling of 820567217 in words is "eight hundred twenty million, five hundred sixty-seven thousand, two hundred seventeen".