819473821 has 2 divisors, whose sum is σ = 819473822. Its totient is φ = 819473820.

The previous prime is 819473813. The next prime is 819473867. The reversal of 819473821 is 128374918.

819473821 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., 584188900 + 235284921 = 24170^2 + 15339^2 .

It is a cyclic number.

It is not a de Polignac number, because 819473821 - 2³ = 819473813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (819473621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409736910 + 409736911.

It is an arithmetic number, because the mean of its divisors is an integer number (409736911).

Almost surely, 2^819473821 is an apocalyptic number.

It is an amenable number.

819473821 is a deficient number, since it is larger than the sum of its proper divisors (1).

819473821 is an equidigital number, since it uses as much as digits as its factorization.

819473821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 43.

The square root of 819473821 is about 28626.4531683546. The cubic root of 819473821 is about 935.7899168883.

The spelling of 819473821 in words is "eight hundred nineteen million, four hundred seventy-three thousand, eight hundred twenty-one".