212121002100 has 144 divisors (see below), whose sum is σ = 703670962176. Its totient is φ = 48328752000.

The previous prime is 212121002087. The next prime is 212121002143. The reversal of 212121002100 is 1200121212.

It is a super-3 number, since 3×212121002100³ (a number of 35 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 490705 + ... + 815495.

It is an arithmetic number, because the mean of its divisors is an integer number (4886603904).

Almost surely, 2^212121002100 is an apocalyptic number.

212121002100 is a gapful number since it is divisible by the number (20) 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 212121002100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (351835481088).

212121002100 is an abundant number, since it is smaller than the sum of its proper divisors (491549960076).

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

212121002100 is a wasteful number, since it uses less digits than its factorization.

212121002100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325126 (or 325119 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 212121002100 its reverse (1200121212), we get a palindrome (213321123312).

The spelling of 212121002100 in words is "two hundred twelve billion, one hundred twenty-one million, two thousand, one hundred".