201218 has 4 divisors (see below), whose sum is σ = 301830. Its totient is φ = 100608.

The previous prime is 201211. The next prime is 201233. The reversal of 201218 is 812102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 162409 + 38809 = 403^2 + 197^2 .

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (201211) by changing a digit.

201218 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50303 + ... + 50306.

2²⁰¹²¹⁸ is an apocalyptic number.

201218 is a deficient number, since it is larger than the sum of its proper divisors (100612).

201218 is a wasteful number, since it uses less digits than its factorization.

201218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100611.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 201218 is about 448.5732938997. The cubic root of 201218 is about 58.5988297048.

The spelling of 201218 in words is "two hundred one thousand, two hundred eighteen".