819110072209 has 27 divisors (see below), whose sum is σ = 975082915569. Its totient is φ = 687256489920.

The previous prime is 819110072197. The next prime is 819110072237. The reversal of 819110072209 is 902270011918.

The square root of 819110072209 is 905047.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 10499076225 + 808610995984 = 102465^2 + 899228^2 .

It is not a de Polignac number, because 819110072209 - 2²¹ = 819107975057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (819110075209) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 129418557 + ... + 129424885.

Almost surely, 2^819110072209 is an apocalyptic number.

819110072209 is the 905047-th square number.

819110072209 is the 452524-th centered octagonal number.

It is an amenable number.

819110072209 is a deficient number, since it is larger than the sum of its proper divisors (155972843360).

819110072209 is an frugal number, since it uses more digits than its factorization.

819110072209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12706 (or 6353 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 40.

The spelling of 819110072209 in words is "eight hundred nineteen billion, one hundred ten million, seventy-two thousand, two hundred nine".