217551225 has 12 divisors (see below), whose sum is σ = 359684816. Its totient is φ = 116027280.

The previous prime is 217551221. The next prime is 217551239. The reversal of 217551225 is 522155712.

It is not a de Polignac number, because 217551225 - 2² = 217551221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 217551192 and 217551201.

It is not an unprimeable number, because it can be changed into a prime (217551221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1450267 + ... + 1450416.

Almost surely, 2^217551225 is an apocalyptic number.

217551225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

217551225 is a deficient number, since it is larger than the sum of its proper divisors (142133591).

217551225 is a wasteful number, since it uses less digits than its factorization.

217551225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2900696 (or 2900691 counting only the distinct ones).

The product of its digits is 7000, while the sum is 30.

The square root of 217551225 is about 14749.6177916582. The cubic root of 217551225 is about 601.4328947415.

The spelling of 217551225 in words is "two hundred seventeen million, five hundred fifty-one thousand, two hundred twenty-five".