818519321 has 2 divisors, whose sum is σ = 818519322. Its totient is φ = 818519320.

The previous prime is 818519293. The next prime is 818519323. The reversal of 818519321 is 123915818.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 570015625 + 248503696 = 23875^2 + 15764^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-818519321 is a prime.

Together with 818519323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (818519323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409259660 + 409259661.

It is an arithmetic number, because the mean of its divisors is an integer number (409259661).

Almost surely, 2^818519321 is an apocalyptic number.

It is an amenable number.

818519321 is a deficient number, since it is larger than the sum of its proper divisors (1).

818519321 is an equidigital number, since it uses as much as digits as its factorization.

818519321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 38.

The square root of 818519321 is about 28609.7766681252. The cubic root of 818519321 is about 935.4264484962.

The spelling of 818519321 in words is "eight hundred eighteen million, five hundred nineteen thousand, three hundred twenty-one".