820857017 has 2 divisors, whose sum is σ = 820857018. Its totient is φ = 820857016.

The previous prime is 820857013. The next prime is 820857047. The reversal of 820857017 is 710758028.

820857017 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., 432806416 + 388050601 = 20804^2 + 19699^2 .

It is a cyclic number.

It is not a de Polignac number, because 820857017 - 2² = 820857013 is a prime.

It is not a weakly prime, because it can be changed into another prime (820857013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410428508 + 410428509.

It is an arithmetic number, because the mean of its divisors is an integer number (410428509).

Almost surely, 2^820857017 is an apocalyptic number.

It is an amenable number.

820857017 is a deficient number, since it is larger than the sum of its proper divisors (1).

820857017 is an equidigital number, since it uses as much as digits as its factorization.

820857017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31360, while the sum is 38.

The square root of 820857017 is about 28650.6023845922. The cubic root of 820857017 is about 936.3161298694.

The spelling of 820857017 in words is "eight hundred twenty million, eight hundred fifty-seven thousand, seventeen".