21444144130909 has 2 divisors, whose sum is σ = 21444144130910. Its totient is φ = 21444144130908.

The previous prime is 21444144130907. The next prime is 21444144131027. The reversal of 21444144130909 is 90903144144412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11976984365284 + 9467159765625 = 3460778^2 + 3076875^2 .

It is a cyclic number.

It is not a de Polignac number, because 21444144130909 - 2¹ = 21444144130907 is a prime.

Together with 21444144130907, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21444144130901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10722072065454 + 10722072065455.

It is an arithmetic number, because the mean of its divisors is an integer number (10722072065455).

Almost surely, 2^{21444144130909} is an apocalyptic number.

It is an amenable number.

21444144130909 is a deficient number, since it is larger than the sum of its proper divisors (1).

21444144130909 is an equidigital number, since it uses as much as digits as its factorization.

21444144130909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 497664, while the sum is 46.

The spelling of 21444144130909 in words is "twenty-one trillion, four hundred forty-four billion, one hundred forty-four million, one hundred thirty thousand, nine hundred nine".