1326821 has 2 divisors, whose sum is σ = 1326822. Its totient is φ = 1326820.

The previous prime is 1326817. The next prime is 1326823. The reversal of 1326821 is 1286231.

1326821 = 814² + 815².

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 664225 + 662596 = 815^2 + 814^2 .

It is a cyclic number.

It is not a de Polignac number, because 1326821 - 2² = 1326817 is a prime.

Together with 1326823, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1326823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 663410 + 663411.

It is an arithmetic number, because the mean of its divisors is an integer number (663411).

2^1326821 is an apocalyptic number.

1326821 is the 815-th centered square number.

It is an amenable number.

1326821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1326821 is an equidigital number, since it uses as much as digits as its factorization.

1326821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576, while the sum is 23.

The square root of 1326821 is about 1151.8771635899. The cubic root of 1326821 is about 109.8847553358.

The spelling of 1326821 in words is "one million, three hundred twenty-six thousand, eight hundred twenty-one".