12121221211 has 16 divisors (see below), whose sum is σ = 13480017408. Its totient is φ = 10805464800.

The previous prime is 12121221199. The next prime is 12121221227. The reversal of 12121221211 is 11212212121.

It is a cyclic number.

It is not a de Polignac number, because 12121221211 - 2¹³ = 12121213019 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12121221011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1328776 + ... + 1337866.

It is an arithmetic number, because the mean of its divisors is an integer number (842501088).

Almost surely, 2^12121221211 is an apocalyptic number.

12121221211 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12121221211 is a deficient number, since it is larger than the sum of its proper divisors (1358796197).

12121221211 is a wasteful number, since it uses less digits than its factorization.

12121221211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11442.

The product of its digits is 32, while the sum is 16.

Adding to 12121221211 its reverse (11212212121), we get a palindrome (23333433332).

It can be divided in two parts, 12121 and 221211, that added together give a palindrome (233332).

The spelling of 12121221211 in words is "twelve billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred eleven".