21204122442013 has 4 divisors (see below), whose sum is σ = 24233282790880. Its totient is φ = 18174962093148.

The previous prime is 21204122441933. The next prime is 21204122442067. The reversal of 21204122442013 is 31024422140212.

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 de Polignac number, because none of the positive numbers 2^k-21204122442013 is a prime.

It is a super-2 number, since 2×21204122442013² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204122442073) 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, 1514580174423 + ... + 1514580174436.

It is an arithmetic number, because the mean of its divisors is an integer number (6058320697720).

Almost surely, 2^{21204122442013} is an apocalyptic number.

It is an amenable number.

21204122442013 is a deficient number, since it is larger than the sum of its proper divisors (3029160348867).

21204122442013 is an equidigital number, since it uses as much as digits as its factorization.

21204122442013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3029160348866.

The product of its (nonzero) digits is 6144, while the sum is 28.

Adding to 21204122442013 its reverse (31024422140212), we get a palindrome (52228544582225).

The spelling of 21204122442013 in words is "twenty-one trillion, two hundred four billion, one hundred twenty-two million, four hundred forty-two thousand, thirteen".