21212020200120 has 32 divisors (see below), whose sum is σ = 63636060600720. Its totient is φ = 5656538720000.

The previous prime is 21212020200083. The next prime is 21212020200121. The reversal of 21212020200120 is 2100202021212.

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 21212020200120.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212020200121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88383417381 + ... + 88383417620.

Almost surely, 2^{21212020200120} is an apocalyptic number.

21212020200120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212020200120 is an abundant number, since it is smaller than the sum of its proper divisors (42424040400600).

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

21212020200120 is a wasteful number, since it uses less digits than its factorization.

21212020200120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176766835015 (or 176766835011 counting only the distinct ones).

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

Adding to 21212020200120 its reverse (2100202021212), we get a palindrome (23312222221332).

The spelling of 21212020200120 in words is "twenty-one trillion, two hundred twelve billion, twenty million, two hundred thousand, one hundred twenty".