826851721 has 2 divisors, whose sum is σ = 826851722. Its totient is φ = 826851720.

The previous prime is 826851713. The next prime is 826851731. The reversal of 826851721 is 127158628.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 825930121 + 921600 = 28739^2 + 960^2 .

It is a cyclic number.

It is not a de Polignac number, because 826851721 - 2³ = 826851713 is a prime.

It is not a weakly prime, because it can be changed into another prime (826851731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 413425860 + 413425861.

It is an arithmetic number, because the mean of its divisors is an integer number (413425861).

Almost surely, 2^826851721 is an apocalyptic number.

It is an amenable number.

826851721 is a deficient number, since it is larger than the sum of its proper divisors (1).

826851721 is an equidigital number, since it uses as much as digits as its factorization.

826851721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 53760, while the sum is 40.

The square root of 826851721 is about 28755.0294905083. The cubic root of 826851721 is about 938.5899036501.

The spelling of 826851721 in words is "eight hundred twenty-six million, eight hundred fifty-one thousand, seven hundred twenty-one".