16565022100225 has 9 divisors (see below), whose sum is σ = 20540652638403. Its totient is φ = 13252001400120.

The previous prime is 16565022100181. The next prime is 16565022100261. The reversal of 16565022100225 is 52200122056561.

The square root of 16565022100225 is 4070015.

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., 5963407956081 + 10601614144144 = 2442009^2 + 3256012^2 .

It is not a de Polignac number, because 16565022100225 - 2¹⁹ = 16565021575937 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 19943074 + ... + 20757076.

Almost surely, 2^{16565022100225} is an apocalyptic number.

16565022100225 is the 4070015-th square number.

16565022100225 is the 2035008-th centered octagonal number.

It is an amenable number.

16565022100225 is a deficient number, since it is larger than the sum of its proper divisors (3975630538178).

16565022100225 is an frugal number, since it uses more digits than its factorization.

16565022100225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1628016 (or 814008 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 37.

Adding to 16565022100225 its reverse (52200122056561), we get a palindrome (68765144156786).

The spelling of 16565022100225 in words is "sixteen trillion, five hundred sixty-five billion, twenty-two million, one hundred thousand, two hundred twenty-five".