218918225 has 12 divisors (see below), whose sum is σ = 271649280. Its totient is φ = 175011600.

The previous prime is 218918221. The next prime is 218918239. The reversal of 218918225 is 522819812.

It is not a de Polignac number, because 218918225 - 2² = 218918221 is a prime.

It is not an unprimeable number, because it can be changed into a prime (218918221) by changing a digit.

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, 54020 + ... + 57930.

It is an arithmetic number, because the mean of its divisors is an integer number (22637440).

Almost surely, 2^218918225 is an apocalyptic number.

218918225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

218918225 is a deficient number, since it is larger than the sum of its proper divisors (52731055).

218918225 is a wasteful number, since it uses less digits than its factorization.

218918225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6160 (or 6155 counting only the distinct ones).

The product of its digits is 23040, while the sum is 38.

The square root of 218918225 is about 14795.8854077747. The cubic root of 218918225 is about 602.6899821556.

The spelling of 218918225 in words is "two hundred eighteen million, nine hundred eighteen thousand, two hundred twenty-five".