21331222013 has 4 divisors (see below), whose sum is σ = 21332091708. Its totient is φ = 21330352320.

The previous prime is 21331221983. The next prime is 21331222057. The reversal of 21331222013 is 31022213312.

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 5506085209 + 15825136804 = 74203^2 + 125798^2 .

It is a cyclic number.

It is not a de Polignac number, because 21331222013 - 2⁸ = 21331221757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331222093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 396956 + ... + 447477.

It is an arithmetic number, because the mean of its divisors is an integer number (5333022927).

Almost surely, 2^21331222013 is an apocalyptic number.

It is an amenable number.

21331222013 is a deficient number, since it is larger than the sum of its proper divisors (869695).

21331222013 is an equidigital number, since it uses as much as digits as its factorization.

21331222013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 869694.

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21331222013 its reverse (31022213312), we get a palindrome (52353435325).

The spelling of 21331222013 in words is "twenty-one billion, three hundred thirty-one million, two hundred twenty-two thousand, thirteen".