21311303213 has 4 divisors (see below), whose sum is σ = 21311970240. Its totient is φ = 21310636188.

The previous prime is 21311303191. The next prime is 21311303227. The reversal of 21311303213 is 31230311312.

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 21311303213 - 2¹⁰ = 21311302189 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21311303243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 283043 + ... + 350336.

It is an arithmetic number, because the mean of its divisors is an integer number (5327992560).

Almost surely, 2^21311303213 is an apocalyptic number.

It is an amenable number.

21311303213 is a deficient number, since it is larger than the sum of its proper divisors (667027).

21311303213 is an equidigital number, since it uses as much as digits as its factorization.

21311303213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667026.

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 21311303213 its reverse (31230311312), we get a palindrome (52541614525).

The spelling of 21311303213 in words is "twenty-one billion, three hundred eleven million, three hundred three thousand, two hundred thirteen".