1212122221212 has 144 divisors (see below), whose sum is σ = 3357619294848. Its totient is φ = 339264858240.

The previous prime is 1212122221207. The next prime is 1212122221213. The reversal of 1212122221212 is 2121222212121.

It is a Harshad number since it is a multiple of its sum of digits (21).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212122221213) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7045683 + ... + 7215669.

Almost surely, 2^{1212122221212} is an apocalyptic number.

1212122221212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1212122221212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1678809647424).

1212122221212 is an abundant number, since it is smaller than the sum of its proper divisors (2145497073636).

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

1212122221212 is a wasteful number, since it uses less digits than its factorization.

1212122221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170256 (or 170247 counting only the distinct ones).

The product of its digits is 256, while the sum is 21.

Adding to 1212122221212 its reverse (2121222212121), we get a palindrome (3333344433333).

Subtracting 1212122221212 from its reverse (2121222212121), we obtain a palindrome (909099990909).

The spelling of 1212122221212 in words is "one trillion, two hundred twelve billion, one hundred twenty-two million, two hundred twenty-one thousand, two hundred twelve".