21351330213 has 4 divisors (see below), whose sum is σ = 28468440288. Its totient is φ = 14234220140.

The previous prime is 21351330193. The next prime is 21351330229. The reversal of 21351330213 is 31203315312.

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 21351330213 - 2⁵ = 21351330181 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21351330233) 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, 3558555033 + ... + 3558555038.

It is an arithmetic number, because the mean of its divisors is an integer number (7117110072).

Almost surely, 2^21351330213 is an apocalyptic number.

It is an amenable number.

21351330213 is a deficient number, since it is larger than the sum of its proper divisors (7117110075).

21351330213 is an equidigital number, since it uses as much as digits as its factorization.

21351330213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7117110074.

The product of its (nonzero) digits is 1620, while the sum is 24.

Adding to 21351330213 its reverse (31203315312), we get a palindrome (52554645525).

The spelling of 21351330213 in words is "twenty-one billion, three hundred fifty-one million, three hundred thirty thousand, two hundred thirteen".