1211221212112 has 20 divisors (see below), whose sum is σ = 2470253788480. Its totient is φ = 573736363488.

The previous prime is 1211221212107. The next prime is 1211221212121. The reversal of 1211221212112 is 2112121221121.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 1211221212112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1992139848 + ... + 1992140455.

It is an arithmetic number, because the mean of its divisors is an integer number (123512689424).

Almost surely, 2^{1211221212112} is an apocalyptic number.

It is an amenable number.

1211221212112 is an abundant number, since it is smaller than the sum of its proper divisors (1259032576368).

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

1211221212112 is a wasteful number, since it uses less digits than its factorization.

1211221212112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3984280330 (or 3984280324 counting only the distinct ones).

The product of its digits is 64, while the sum is 19.

Adding to 1211221212112 its reverse (2112121221121), we get a palindrome (3323342433233).

Subtracting 1211221212112 from its reverse (2112121221121), we obtain a palindrome (900900009009).

It can be divided in two parts, 12112212 and 12112, that added together give a square (12124324 = 3482²).

The spelling of 1211221212112 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, two hundred twelve thousand, one hundred twelve".