21344042105 has 4 divisors (see below), whose sum is σ = 25612850532. Its totient is φ = 17075233680.

The previous prime is 21344042077. The next prime is 21344042149. The reversal of 21344042105 is 50124044312.

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 13467834601 + 7876207504 = 116051^2 + 88748^2 .

It is not a de Polignac number, because 21344042105 - 2¹⁶ = 21343976569 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2134404206 + ... + 2134404215.

It is an arithmetic number, because the mean of its divisors is an integer number (6403212633).

Almost surely, 2^21344042105 is an apocalyptic number.

It is an amenable number.

21344042105 is a deficient number, since it is larger than the sum of its proper divisors (4268808427).

21344042105 is an equidigital number, since it uses as much as digits as its factorization.

21344042105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4268808426.

The product of its (nonzero) digits is 3840, while the sum is 26.

Adding to 21344042105 its reverse (50124044312), we get a palindrome (71468086417).

The spelling of 21344042105 in words is "twenty-one billion, three hundred forty-four million, forty-two thousand, one hundred five".