821078417 has 2 divisors, whose sum is σ = 821078418. Its totient is φ = 821078416.

The previous prime is 821078411. The next prime is 821078441. The reversal of 821078417 is 714870128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 819333376 + 1745041 = 28624^2 + 1321^2 .

It is a cyclic number.

It is not a de Polignac number, because 821078417 - 2¹⁰ = 821077393 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (821078411) 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, 410539208 + 410539209.

It is an arithmetic number, because the mean of its divisors is an integer number (410539209).

Almost surely, 2^821078417 is an apocalyptic number.

It is an amenable number.

821078417 is a deficient number, since it is larger than the sum of its proper divisors (1).

821078417 is an equidigital number, since it uses as much as digits as its factorization.

821078417 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25088, while the sum is 38.

The square root of 821078417 is about 28654.4659172004. The cubic root of 821078417 is about 936.4003027733.

The spelling of 821078417 in words is "eight hundred twenty-one million, seventy-eight thousand, four hundred seventeen".