21443110505 has 4 divisors (see below), whose sum is σ = 25731732612. Its totient is φ = 17154488400.

The previous prime is 21443110489. The next prime is 21443110537. The reversal of 21443110505 is 50501134412.

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 14327850601 + 7115259904 = 119699^2 + 84352^2 .

It is not a de Polignac number, because 21443110505 - 2⁴ = 21443110489 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, 2144311046 + ... + 2144311055.

It is an arithmetic number, because the mean of its divisors is an integer number (6432933153).

Almost surely, 2^21443110505 is an apocalyptic number.

It is an amenable number.

21443110505 is a deficient number, since it is larger than the sum of its proper divisors (4288622107).

21443110505 is an equidigital number, since it uses as much as digits as its factorization.

21443110505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4288622106.

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 21443110505 its reverse (50501134412), we get a palindrome (71944244917).

The spelling of 21443110505 in words is "twenty-one billion, four hundred forty-three million, one hundred ten thousand, five hundred five".