813821295289 has 4 divisors (see below), whose sum is σ = 813908465524. Its totient is φ = 813734125056.

The previous prime is 813821295281. The next prime is 813821295311. The reversal of 813821295289 is 982592128318.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 803255100025 + 10566195264 = 896245^2 + 102792^2 .

It is a 3-Lehmer number, since φ(813821295289) divides (813821295289-1)³.

It is a cyclic number.

It is not a de Polignac number, because 813821295289 - 2³ = 813821295281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (813821295281) by changing a digit.

It is a nontrivial repunit in base 9336.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43571112 + ... + 43589785.

It is an arithmetic number, because the mean of its divisors is an integer number (203477116381).

Almost surely, 2^813821295289 is an apocalyptic number.

It is an amenable number.

813821295289 is a deficient number, since it is larger than the sum of its proper divisors (87170235).

813821295289 is an equidigital number, since it uses as much as digits as its factorization.

813821295289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87170234.

The product of its digits is 4976640, while the sum is 58.

The spelling of 813821295289 in words is "eight hundred thirteen billion, eight hundred twenty-one million, two hundred ninety-five thousand, two hundred eighty-nine".