1212212021100 has 144 divisors (see below), whose sum is σ = 3528757395072. Its totient is φ = 321287037440.

The previous prime is 1212212021071. The next prime is 1212212021161. The reversal of 1212212021100 is 11202122121.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1212212021100.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 39338299 + ... + 39369101.

It is an arithmetic number, because the mean of its divisors is an integer number (24505259688).

Almost surely, 2^{1212212021100} is an apocalyptic number.

1212212021100 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 1212212021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1764378697536).

1212212021100 is an abundant number, since it is smaller than the sum of its proper divisors (2316545373972).

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

1212212021100 is a wasteful number, since it uses less digits than its factorization.

1212212021100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31616 (or 31609 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1212212021100 its reverse (11202122121), we get a palindrome (1223414143221).

The spelling of 1212212021100 in words is "one trillion, two hundred twelve billion, two hundred twelve million, twenty-one thousand, one hundred".