21344344121 has 4 divisors (see below), whose sum is σ = 21373227600. Its totient is φ = 21315460644.

The previous prime is 21344344111. The next prime is 21344344129. The reversal of 21344344121 is 12144344312.

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 a de Polignac number, because none of the positive numbers 2^k-21344344121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21344344129) 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, 14440631 + ... + 14442108.

It is an arithmetic number, because the mean of its divisors is an integer number (5343306900).

Almost surely, 2^21344344121 is an apocalyptic number.

It is an amenable number.

21344344121 is a deficient number, since it is larger than the sum of its proper divisors (28883479).

21344344121 is an equidigital number, since it uses as much as digits as its factorization.

21344344121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28883478.

The product of its digits is 9216, while the sum is 29.

Adding to 21344344121 its reverse (12144344312), we get a palindrome (33488688433).

The spelling of 21344344121 in words is "twenty-one billion, three hundred forty-four million, three hundred forty-four thousand, one hundred twenty-one".