1212211221100 has 288 divisors, whose sum is σ = 3095306887680. Its totient is φ = 407666688000.

The previous prime is 1212211221097. The next prime is 1212211221101. The reversal of 1212211221100 is 11221122121.

It is not an unprimeable number, because it can be changed into a prime (1212211221101) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 91048044 + ... + 91061356.

It is an arithmetic number, because the mean of its divisors is an integer number (10747593360).

Almost surely, 2^{1212211221100} is an apocalyptic number.

1212211221100 is a gapful number since it is divisible by the number (10) 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 1212211221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1547653443840).

1212211221100 is an abundant number, since it is smaller than the sum of its proper divisors (1883095666580).

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

1212211221100 is a wasteful number, since it uses less digits than its factorization.

1212211221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13481 (or 13474 counting only the distinct ones).

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

Adding to 1212211221100 its reverse (11221122121), we get a palindrome (1223432343221).

The spelling of 1212211221100 in words is "one trillion, two hundred twelve billion, two hundred eleven million, two hundred twenty-one thousand, one hundred".