216722836225 has 81 divisors (see below), whose sum is σ = 320537088387. Its totient is φ = 144934080480.

The previous prime is 216722836181. The next prime is 216722836229. The reversal of 216722836225 is 522638227612.

The square root of 216722836225 is 465535.

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., 78020221041 + 138702615184 = 279321^2 + 372428^2 .

It is not a de Polignac number, because 216722836225 - 2⁷ = 216722836097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216722836229) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 765804934 + ... + 765805216.

Almost surely, 2^216722836225 is an apocalyptic number.

216722836225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

216722836225 is the 465535-th square number.

216722836225 is the 232768-th centered octagonal number.

It is an amenable number.

216722836225 is a deficient number, since it is larger than the sum of its proper divisors (103814252162).

216722836225 is an frugal number, since it uses more digits than its factorization.

216722836225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 684 (or 342 counting only the distinct ones).

The product of its digits is 967680, while the sum is 46.

The spelling of 216722836225 in words is "two hundred sixteen billion, seven hundred twenty-two million, eight hundred thirty-six thousand, two hundred twenty-five".