217850895025 has 27 divisors (see below), whose sum is σ = 271920726819. Its totient is φ = 173136257280.

The previous prime is 217850894957. The next prime is 217850895109. The reversal of 217850895025 is 520598058712.

The square root of 217850895025 is 466745.

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

It can be written as a sum of positive squares in 13 ways, for example, as 217373210289 + 477684736 = 466233^2 + 21856^2 .

It is not a de Polignac number, because 217850895025 - 2¹¹ = 217850892977 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 646441657 + ... + 646441993.

Almost surely, 2^217850895025 is an apocalyptic number.

217850895025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

217850895025 is the 466745-th square number.

217850895025 is the 233373-rd centered octagonal number.

It is an amenable number.

217850895025 is a deficient number, since it is larger than the sum of its proper divisors (54069831794).

217850895025 is an frugal number, since it uses more digits than its factorization.

217850895025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1238 (or 619 counting only the distinct ones).

The product of its (nonzero) digits is 2016000, while the sum is 52.

The spelling of 217850895025 in words is "two hundred seventeen billion, eight hundred fifty million, eight hundred ninety-five thousand, twenty-five".