821461 has 2 divisors, whose sum is σ = 821462. Its totient is φ = 821460.

The previous prime is 821459. The next prime is 821467. The reversal of 821461 is 164128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 820836 + 625 = 906^2 + 25^2 .

It is a cyclic number.

It is not a de Polignac number, because 821461 - 2¹ = 821459 is a prime.

Together with 821459, it forms a pair of twin primes.

It is a Chen prime.

821461 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (821467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410730 + 410731.

It is an arithmetic number, because the mean of its divisors is an integer number (410731).

2⁸²¹⁴⁶¹ is an apocalyptic number.

It is an amenable number.

821461 is a deficient number, since it is larger than the sum of its proper divisors (1).

821461 is an equidigital number, since it uses as much as digits as its factorization.

821461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 384, while the sum is 22.

The square root of 821461 is about 906.3448571046. The cubic root of 821461 is about 93.6545719338.

Adding to 821461 its reverse (164128), we get a palindrome (985589).

The spelling of 821461 in words is "eight hundred twenty-one thousand, four hundred sixty-one".