819487321 has 4 divisors (see below), whose sum is σ = 819700452. Its totient is φ = 819274192.

The previous prime is 819487297. The next prime is 819487327. The reversal of 819487321 is 123784918.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 123784918 = 2 ⋅61892459.

It can be written as a sum of positive squares in 2 ways, for example, as 288830025 + 530657296 = 16995^2 + 23036^2 .

It is a cyclic number.

It is not a de Polignac number, because 819487321 - 2⁵ = 819487289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (819487327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100690 + ... + 108523.

It is an arithmetic number, because the mean of its divisors is an integer number (204925113).

Almost surely, 2^819487321 is an apocalyptic number.

It is an amenable number.

819487321 is a deficient number, since it is larger than the sum of its proper divisors (213131).

819487321 is a wasteful number, since it uses less digits than its factorization.

819487321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213130.

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

The square root of 819487321 is about 28626.6889632734. The cubic root of 819487321 is about 935.7950555900.

The spelling of 819487321 in words is "eight hundred nineteen million, four hundred eighty-seven thousand, three hundred twenty-one".