821741 has 2 divisors, whose sum is σ = 821742. Its totient is φ = 821740.

The previous prime is 821677. The next prime is 821747. The reversal of 821741 is 147128.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 556516 + 265225 = 746^2 + 515^2 .

It is a cyclic number.

It is not a de Polignac number, because 821741 - 2⁶ = 821677 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (821747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410870 + 410871.

It is an arithmetic number, because the mean of its divisors is an integer number (410871).

2⁸²¹⁷⁴¹ is an apocalyptic number.

It is an amenable number.

821741 is a deficient number, since it is larger than the sum of its proper divisors (1).

821741 is an equidigital number, since it uses as much as digits as its factorization.

821741 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 448, while the sum is 23.

The square root of 821741 is about 906.4993105348. The cubic root of 821741 is about 93.6652116360.

Adding to 821741 its reverse (147128), we get a palindrome (968869).

The spelling of 821741 in words is "eight hundred twenty-one thousand, seven hundred forty-one".