221212220210 has 16 divisors (see below), whose sum is σ = 398193598296. Its totient is φ = 88482309888.

The previous prime is 221212220153. The next prime is 221212220239. The reversal of 221212220210 is 12022212122.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 163936721881 + 57275498329 = 404891^2 + 239323^2 .

It is an unprimeable number.

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, 59642 + ... + 667818.

Almost surely, 2^221212220210 is an apocalyptic number.

221212220210 is a deficient number, since it is larger than the sum of its proper divisors (176981378086).

221212220210 is a wasteful number, since it uses less digits than its factorization.

221212220210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 644557.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 221212220210 its reverse (12022212122), we get a palindrome (233234432332).

The spelling of 221212220210 in words is "two hundred twenty-one billion, two hundred twelve million, two hundred twenty thousand, two hundred ten".