21210200002121 has 16 divisors (see below), whose sum is σ = 22880077248000. Its totient is φ = 19545823946880.

The previous prime is 21210200002039. The next prime is 21210200002127. The reversal of 21210200002121 is 12120000201212.

It is a cyclic number.

It is not a de Polignac number, because 21210200002121 - 2¹⁰ = 21210200001097 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21210200002096 and 21210200002105.

It is not an unprimeable number, because it can be changed into a prime (21210200002127) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 18762461 + ... + 19860773.

It is an arithmetic number, because the mean of its divisors is an integer number (1430004828000).

Almost surely, 2^{21210200002121} is an apocalyptic number.

It is an amenable number.

21210200002121 is a deficient number, since it is larger than the sum of its proper divisors (1669877245879).

21210200002121 is a wasteful number, since it uses less digits than its factorization.

21210200002121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1100816.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21210200002121 its reverse (12120000201212), we get a palindrome (33330200203333).

The spelling of 21210200002121 in words is "twenty-one trillion, two hundred ten billion, two hundred million, two thousand, one hundred twenty-one".