221212020002100 has 144 divisors (see below), whose sum is σ = 657368435894016. Its totient is φ = 57392936640000.

The previous prime is 221212020002027. The next prime is 221212020002143. The reversal of 221212020002100 is 1200020212122.

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 221212020002100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 249429450 + ... + 250314750.

Almost surely, 2^{221212020002100} is an apocalyptic number.

221212020002100 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 221212020002100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (328684217947008).

221212020002100 is an abundant number, since it is smaller than the sum of its proper divisors (436156415891916).

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

221212020002100 is a wasteful number, since it uses less digits than its factorization.

221212020002100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 907866 (or 907859 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 221212020002100 its reverse (1200020212122), we get a palindrome (222412040214222).

The spelling of 221212020002100 in words is "two hundred twenty-one trillion, two hundred twelve billion, twenty million, two thousand, one hundred".