819209609 has 2 divisors, whose sum is σ = 819209610. Its totient is φ = 819209608.

The previous prime is 819209597. The next prime is 819209621. The reversal of 819209609 is 906902918.

It is a balanced prime because it is at equal distance from previous prime (819209597) and next prime (819209621).

It can be written as a sum of positive squares in only one way, i.e., 816816400 + 2393209 = 28580^2 + 1547^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-819209609 is a prime.

It is a super-2 number, since 2×819209609² = 1342208766955865762, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 819209609.

It is not a weakly prime, because it can be changed into another prime (819209669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409604804 + 409604805.

It is an arithmetic number, because the mean of its divisors is an integer number (409604805).

Almost surely, 2^819209609 is an apocalyptic number.

It is an amenable number.

819209609 is a deficient number, since it is larger than the sum of its proper divisors (1).

819209609 is an equidigital number, since it uses as much as digits as its factorization.

819209609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 44.

The square root of 819209609 is about 28621.8379738269. The cubic root of 819209609 is about 935.6893346626.

The spelling of 819209609 in words is "eight hundred nineteen million, two hundred nine thousand, six hundred nine".