21321113313 has 4 divisors (see below), whose sum is σ = 28428151088. Its totient is φ = 14214075540.

The previous prime is 21321113263. The next prime is 21321113353. The reversal of 21321113313 is 31331112312.

It is a happy number.

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 not a de Polignac number, because 21321113313 - 2⁹ = 21321112801 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21321113313.

It is not an unprimeable number, because it can be changed into a prime (21321113353) 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, 3553518883 + ... + 3553518888.

It is an arithmetic number, because the mean of its divisors is an integer number (7107037772).

Almost surely, 2^21321113313 is an apocalyptic number.

It is an amenable number.

21321113313 is a deficient number, since it is larger than the sum of its proper divisors (7107037775).

21321113313 is an equidigital number, since it uses as much as digits as its factorization.

21321113313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7107037774.

The product of its digits is 324, while the sum is 21.

Adding to 21321113313 its reverse (31331112312), we get a palindrome (52652225625).

The spelling of 21321113313 in words is "twenty-one billion, three hundred twenty-one million, one hundred thirteen thousand, three hundred thirteen".