21021210213 has 4 divisors (see below), whose sum is σ = 28028280288. Its totient is φ = 14014140140.

The previous prime is 21021210211. The next prime is 21021210227. The reversal of 21021210213 is 31201212012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21021210213 - 2¹ = 21021210211 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21021210192 and 21021210201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021210211) 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 in 3 ways as a sum of consecutive naturals, for example, 3503535033 + ... + 3503535038.

It is an arithmetic number, because the mean of its divisors is an integer number (7007070072).

Almost surely, 2^21021210213 is an apocalyptic number.

It is an amenable number.

21021210213 is a deficient number, since it is larger than the sum of its proper divisors (7007070075).

21021210213 is an equidigital number, since it uses as much as digits as its factorization.

21021210213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7007070074.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21021210213 its reverse (31201212012), we get a palindrome (52222422225).

The spelling of 21021210213 in words is "twenty-one billion, twenty-one million, two hundred ten thousand, two hundred thirteen".