218616225 has 12 divisors (see below), whose sum is σ = 361445616. Its totient is φ = 116595280.

The previous prime is 218616191. The next prime is 218616259. The reversal of 218616225 is 522616812.

It is an interprime number because it is at equal distance from previous prime (218616191) and next prime (218616259).

It is not a de Polignac number, because 218616225 - 2¹⁷ = 218485153 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1457367 + ... + 1457516.

It is an arithmetic number, because the mean of its divisors is an integer number (30120468).

Almost surely, 2^218616225 is an apocalyptic number.

218616225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

218616225 is a deficient number, since it is larger than the sum of its proper divisors (142829391).

218616225 is a wasteful number, since it uses less digits than its factorization.

218616225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2914896 (or 2914891 counting only the distinct ones).

The product of its digits is 11520, while the sum is 33.

The square root of 218616225 is about 14785.6763457070. The cubic root of 218616225 is about 602.4127155571.

The spelling of 218616225 in words is "two hundred eighteen million, six hundred sixteen thousand, two hundred twenty-five".