821827717 has 2 divisors, whose sum is σ = 821827718. Its totient is φ = 821827716.

The previous prime is 821827711. The next prime is 821827771. The reversal of 821827717 is 717728128.

Together with next prime (821827771) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 680479396 + 141348321 = 26086^2 + 11889^2 .

It is a cyclic number.

It is not a de Polignac number, because 821827717 - 2³ = 821827709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (821827711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410913858 + 410913859.

It is an arithmetic number, because the mean of its divisors is an integer number (410913859).

Almost surely, 2^821827717 is an apocalyptic number.

It is an amenable number.

821827717 is a deficient number, since it is larger than the sum of its proper divisors (1).

821827717 is an equidigital number, since it uses as much as digits as its factorization.

821827717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 87808, while the sum is 43.

The square root of 821827717 is about 28667.5376863797. The cubic root of 821827717 is about 936.6850629963.

The spelling of 821827717 in words is "eight hundred twenty-one million, eight hundred twenty-seven thousand, seven hundred seventeen".