1212221211 has 24 divisors (see below), whose sum is σ = 1664666112. Its totient is φ = 784641600.

The previous prime is 1212221191. The next prime is 1212221221. The reversal of 1212221211 is 1121222121.

It is a de Polignac number, because none of the positive numbers 2^k-1212221211 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1212221221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1366210 + ... + 1367096.

It is an arithmetic number, because the mean of its divisors is an integer number (69361088).

Almost surely, 2^1212221211 is an apocalyptic number.

1212221211 is a deficient number, since it is larger than the sum of its proper divisors (452444901).

1212221211 is an equidigital number, since it uses as much as digits as its factorization.

1212221211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1243 (or 1202 counting only the distinct ones).

The product of its digits is 32, while the sum is 15.

The square root of 1212221211 is about 34816.9672860805. The cubic root of 1212221211 is about 1066.2538843019.

Adding to 1212221211 its reverse (1121222121), we get a palindrome (2333443332).

It can be divided in two parts, 12122 and 21211, that added together give a palindrome (33333).

The spelling of 1212221211 in words is "one billion, two hundred twelve million, two hundred twenty-one thousand, two hundred eleven".