836821 has 2 divisors, whose sum is σ = 836822. Its totient is φ = 836820.

The previous prime is 836807. The next prime is 836833. The reversal of 836821 is 128638.

836821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 600625 + 236196 = 775^2 + 486^2 .

It is a cyclic number.

It is not a de Polignac number, because 836821 - 2⁵ = 836789 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 836821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (836861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 418410 + 418411.

It is an arithmetic number, because the mean of its divisors is an integer number (418411).

2⁸³⁶⁸²¹ is an apocalyptic number.

It is an amenable number.

836821 is a deficient number, since it is larger than the sum of its proper divisors (1).

836821 is an equidigital number, since it uses as much as digits as its factorization.

836821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 28.

The square root of 836821 is about 914.7792083339. The cubic root of 836821 is about 94.2347009669.

The spelling of 836821 in words is "eight hundred thirty-six thousand, eight hundred twenty-one".