1212211209 has 32 divisors (see below), whose sum is σ = 1800906624. Its totient is φ = 719124480.

The previous prime is 1212211201. The next prime is 1212211213. The reversal of 1212211209 is 9021122121.

It is not a de Polignac number, because 1212211209 - 2³ = 1212211201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1212211201) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 328197 + ... + 331869.

It is an arithmetic number, because the mean of its divisors is an integer number (56278332).

Almost surely, 2^1212211209 is an apocalyptic number.

It is an amenable number.

1212211209 is a deficient number, since it is larger than the sum of its proper divisors (588695415).

1212211209 is a wasteful number, since it uses less digits than its factorization.

1212211209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3897.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 1212211209 is about 34816.8236489201. The cubic root of 1212211209 is about 1066.2509517512.

It can be divided in two parts, 12 and 12211209, that added together give a palindrome (12211221).

The spelling of 1212211209 in words is "one billion, two hundred twelve million, two hundred eleven thousand, two hundred nine".