21303213120121 has 4 divisors (see below), whose sum is σ = 21303604281700. Its totient is φ = 21302821958544.

The previous prime is 21303213120029. The next prime is 21303213120181. The reversal of 21303213120121 is 12102131230312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9918493604496 + 11384719515625 = 3149364^2 + 3374125^2 .

It is a cyclic number.

It is not a de Polignac number, because 21303213120121 - 2¹¹ = 21303213118073 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21303213120092 and 21303213120101.

It is not an unprimeable number, because it can be changed into a prime (21303213120181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 195499086 + ... + 195608023.

It is an arithmetic number, because the mean of its divisors is an integer number (5325901070425).

Almost surely, 2^{21303213120121} is an apocalyptic number.

It is an amenable number.

21303213120121 is a deficient number, since it is larger than the sum of its proper divisors (391161579).

21303213120121 is an equidigital number, since it uses as much as digits as its factorization.

21303213120121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391161578.

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 21303213120121 its reverse (12102131230312), we get a palindrome (33405344350433).

The spelling of 21303213120121 in words is "twenty-one trillion, three hundred three billion, two hundred thirteen million, one hundred twenty thousand, one hundred twenty-one".