821278841 has 2 divisors, whose sum is σ = 821278842. Its totient is φ = 821278840.

The previous prime is 821278837. The next prime is 821278847. The reversal of 821278841 is 148872128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 727111225 + 94167616 = 26965^2 + 9704^2 .

It is a cyclic number.

It is not a de Polignac number, because 821278841 - 2² = 821278837 is a prime.

It is a super-3 number, since 3×821278841³ (a number of 28 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (821278847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410639420 + 410639421.

It is an arithmetic number, because the mean of its divisors is an integer number (410639421).

Almost surely, 2^821278841 is an apocalyptic number.

It is an amenable number.

821278841 is a deficient number, since it is larger than the sum of its proper divisors (1).

821278841 is an equidigital number, since it uses as much as digits as its factorization.

821278841 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 57344, while the sum is 41.

The square root of 821278841 is about 28657.9629597081. The cubic root of 821278841 is about 936.4764878741.

The spelling of 821278841 in words is "eight hundred twenty-one million, two hundred seventy-eight thousand, eight hundred forty-one".