821443969 has 2 divisors, whose sum is σ = 821443970. Its totient is φ = 821443968.

The previous prime is 821443949. The next prime is 821443999. The reversal of 821443969 is 969344128.

821443969 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 550512369 + 270931600 = 23463^2 + 16460^2 .

It is a cyclic number.

It is not a de Polignac number, because 821443969 - 2²³ = 813055361 is a prime.

It is a super-2 number, since 2×821443969² = 1349540388412945922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (821443949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410721984 + 410721985.

It is an arithmetic number, because the mean of its divisors is an integer number (410721985).

Almost surely, 2^821443969 is an apocalyptic number.

It is an amenable number.

821443969 is a deficient number, since it is larger than the sum of its proper divisors (1).

821443969 is an equidigital number, since it uses as much as digits as its factorization.

821443969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 46.

The square root of 821443969 is about 28660.8438291687. The cubic root of 821443969 is about 936.5392469594.

The spelling of 821443969 in words is "eight hundred twenty-one million, four hundred forty-three thousand, nine hundred sixty-nine".