1212121021100 has 216 divisors, whose sum is σ = 3010938370944. Its totient is φ = 422763264000.

The previous prime is 1212121021049. The next prime is 1212121021117. The reversal of 1212121021100 is 11201212121.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 42372002 + ... + 42400598.

Almost surely, 2^{1212121021100} is an apocalyptic number.

1212121021100 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 1212121021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1505469185472).

1212121021100 is an abundant number, since it is smaller than the sum of its proper divisors (1798817349844).

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

1212121021100 is a wasteful number, since it uses less digits than its factorization.

1212121021100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28777 (or 28759 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1212121021100 its reverse (11201212121), we get a palindrome (1223322233221).

The spelling of 1212121021100 in words is "one trillion, two hundred twelve billion, one hundred twenty-one million, twenty-one thousand, one hundred".