878821 has 2 divisors, whose sum is σ = 878822. Its totient is φ = 878820.

The previous prime is 878797. The next prime is 878831. The reversal of 878821 is 128878.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 662596 + 216225 = 814^2 + 465^2 .

It is a cyclic number.

It is not a de Polignac number, because 878821 - 2⁵ = 878789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (878831) 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, 439410 + 439411.

It is an arithmetic number, because the mean of its divisors is an integer number (439411).

2⁸⁷⁸⁸²¹ is an apocalyptic number.

It is an amenable number.

878821 is a deficient number, since it is larger than the sum of its proper divisors (1).

878821 is an equidigital number, since it uses as much as digits as its factorization.

878821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7168, while the sum is 34.

The square root of 878821 is about 937.4545322308. The cubic root of 878821 is about 95.7855819237.

The spelling of 878821 in words is "eight hundred seventy-eight thousand, eight hundred twenty-one".