217252006609 has 9 divisors (see below), whose sum is σ = 238803295899. Its totient is φ = 197497163160.

The previous prime is 217252006597. The next prime is 217252006627. The reversal of 217252006609 is 906600252712.

The square root of 217252006609 is 466103.

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., 12379900225 + 204872106384 = 111265^2 + 452628^2 .

It is not a de Polignac number, because 217252006609 - 2²⁵ = 217218452177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217252006639) 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, 5105947 + ... + 5148319.

Almost surely, 2^217252006609 is an apocalyptic number.

217252006609 is the 466103-rd square number.

217252006609 is the 233052-nd centered octagonal number.

It is an amenable number.

217252006609 is a deficient number, since it is larger than the sum of its proper divisors (21551289290).

217252006609 is an frugal number, since it uses more digits than its factorization.

217252006609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84768 (or 42384 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 40.

The spelling of 217252006609 in words is "two hundred seventeen billion, two hundred fifty-two million, six thousand, six hundred nine".