411821 has 2 divisors, whose sum is σ = 411822. Its totient is φ = 411820.

The previous prime is 411809. The next prime is 411823. The reversal of 411821 is 128114.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 366025 + 45796 = 605^2 + 214^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-411821 is a prime.

It is a Sophie Germain prime.

Together with 411823, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 411821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (411823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205910 + 205911.

It is an arithmetic number, because the mean of its divisors is an integer number (205911).

2⁴¹¹⁸²¹ is an apocalyptic number.

It is an amenable number.

411821 is a deficient number, since it is larger than the sum of its proper divisors (1).

411821 is an equidigital number, since it uses as much as digits as its factorization.

411821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64, while the sum is 17.

The square root of 411821 is about 641.7328104437. The cubic root of 411821 is about 74.3994108135.

Adding to 411821 its reverse (128114), we get a palindrome (539935).

It can be divided in two parts, 411 and 821, that multiplied together give a triangular number (337431 = T₈₂₁).

The spelling of 411821 in words is "four hundred eleven thousand, eight hundred twenty-one".