21444503191 has 2 divisors, whose sum is σ = 21444503192. Its totient is φ = 21444503190.

The previous prime is 21444503189. The next prime is 21444503207. The reversal of 21444503191 is 19130544412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21444503191 - 2¹ = 21444503189 is a prime.

Together with 21444503189, 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 (21444503111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10722251595 + 10722251596.

It is an arithmetic number, because the mean of its divisors is an integer number (10722251596).

Almost surely, 2^21444503191 is an apocalyptic number.

21444503191 is a deficient number, since it is larger than the sum of its proper divisors (1).

21444503191 is an equidigital number, since it uses as much as digits as its factorization.

21444503191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 34.

The spelling of 21444503191 in words is "twenty-one billion, four hundred forty-four million, five hundred three thousand, one hundred ninety-one".