817300978209 has 9 divisors (see below), whose sum is σ = 1180549774963. Its totient is φ = 544865510712.

The previous prime is 817300978181. The next prime is 817300978211. The reversal of 817300978209 is 902879003718.

The square root of 817300978209 is 904047.

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

It can be written as a sum of positive squares in only one way, i.e., 610512510609 + 206788467600 = 781353^2 + 454740^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 817300978209 - 2⁵ = 817300978177 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (817300978709) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2561467 + ... + 2862815.

Almost surely, 2^817300978209 is an apocalyptic number.

817300978209 is the 904047-th square number.

817300978209 is the 452024-th centered octagonal number.

It is an amenable number.

817300978209 is a deficient number, since it is larger than the sum of its proper divisors (363248796754).

817300978209 is an frugal number, since it uses more digits than its factorization.

817300978209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 602704 (or 301352 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 54.

The spelling of 817300978209 in words is "eight hundred seventeen billion, three hundred million, nine hundred seventy-eight thousand, two hundred nine".