21210200010121 has 2 divisors, whose sum is σ = 21210200010122. Its totient is φ = 21210200010120.

The previous prime is 21210200010067. The next prime is 21210200010157. The reversal of 21210200010121 is 12101000201212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19055363910025 + 2154836100096 = 4365245^2 + 1467936^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210200010121 - 2¹⁷ = 21210199879049 is a prime.

It is not a weakly prime, because it can be changed into another prime (21210200010161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605100005060 + 10605100005061.

It is an arithmetic number, because the mean of its divisors is an integer number (10605100005061).

Almost surely, 2^{21210200010121} is an apocalyptic number.

It is an amenable number.

21210200010121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210200010121 is an equidigital number, since it uses as much as digits as its factorization.

21210200010121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21210200010121 its reverse (12101000201212), we get a palindrome (33311200211333).

The spelling of 21210200010121 in words is "twenty-one trillion, two hundred ten billion, two hundred million, ten thousand, one hundred twenty-one".