217107272225 has 18 divisors (see below), whose sum is σ = 273853397670. Its totient is φ = 170741921920.

The previous prime is 217107272177. The next prime is 217107272257. The reversal of 217107272225 is 522272701712.

It can be written as a sum of positive squares in 3 ways, for example, as 2927134609 + 214180137616 = 54103^2 + 462796^2 .

It is a de Polignac number, because none of the positive numbers 2^k-217107272225 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1160360 + ... + 1334409.

Almost surely, 2^217107272225 is an apocalyptic number.

217107272225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

217107272225 is a deficient number, since it is larger than the sum of its proper divisors (56746125445).

217107272225 is an equidigital number, since it uses as much as digits as its factorization.

217107272225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2494897 (or 2494833 counting only the distinct ones).

The product of its (nonzero) digits is 54880, while the sum is 38.

Adding to 217107272225 its reverse (522272701712), we get a palindrome (739379973937).

The spelling of 217107272225 in words is "two hundred seventeen billion, one hundred seven million, two hundred seventy-two thousand, two hundred twenty-five".