521812218 has 16 divisors (see below), whose sum is σ = 1043852256. Its totient is φ = 173899440.

The previous prime is 521812217. The next prime is 521812237. The reversal of 521812218 is 812218125.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (521812217) 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 7 ways as a sum of consecutive naturals, for example, 40708 + ... + 51968.

It is an arithmetic number, because the mean of its divisors is an integer number (65240766).

Almost surely, 2^521812218 is an apocalyptic number.

521812218 is an abundant number, since it is smaller than the sum of its proper divisors (522040038).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

521812218 is a wasteful number, since it uses less digits than its factorization.

521812218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18989.

The product of its digits is 2560, while the sum is 30.

The square root of 521812218 is about 22843.2094505129. The cubic root of 521812218 is about 805.0782265197.

The spelling of 521812218 in words is "five hundred twenty-one million, eight hundred twelve thousand, two hundred eighteen".