21210131210321 has 2 divisors, whose sum is σ = 21210131210322. Its totient is φ = 21210131210320.

The previous prime is 21210131210299. The next prime is 21210131210357. The reversal of 21210131210321 is 12301213101212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17822455372225 + 3387675838096 = 4221665^2 + 1840564^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210131210321 - 2¹⁰ = 21210131209297 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21210131210293 and 21210131210302.

It is not a weakly prime, because it can be changed into another prime (21210131216321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605065605160 + 10605065605161.

It is an arithmetic number, because the mean of its divisors is an integer number (10605065605161).

Almost surely, 2^{21210131210321} is an apocalyptic number.

It is an amenable number.

21210131210321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210131210321 is an equidigital number, since it uses as much as digits as its factorization.

21210131210321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 21210131210321 its reverse (12301213101212), we get a palindrome (33511344311533).

The spelling of 21210131210321 in words is "twenty-one trillion, two hundred ten billion, one hundred thirty-one million, two hundred ten thousand, three hundred twenty-one".