820857013 has 2 divisors, whose sum is σ = 820857014. Its totient is φ = 820857012.

The previous prime is 820856983. The next prime is 820857017. The reversal of 820857013 is 310758028.

820857013 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 663680644 + 157176369 = 25762^2 + 12537^2 .

It is a cyclic number.

It is not a de Polignac number, because 820857013 - 2⁹ = 820856501 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 820857013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (820857017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410428506 + 410428507.

It is an arithmetic number, because the mean of its divisors is an integer number (410428507).

Almost surely, 2^820857013 is an apocalyptic number.

It is an amenable number.

820857013 is a deficient number, since it is larger than the sum of its proper divisors (1).

820857013 is an equidigital number, since it uses as much as digits as its factorization.

820857013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 820857013 is about 28650.6023147856. The cubic root of 820857013 is about 936.3161283485.

It can be divided in two parts, 82085 and 7013, that added together give a palindrome (89098).

The spelling of 820857013 in words is "eight hundred twenty million, eight hundred fifty-seven thousand, thirteen".