21243445005 has 16 divisors (see below), whose sum is σ = 34818525504. Its totient is φ = 11053499520.

The previous prime is 21243444889. The next prime is 21243445009. The reversal of 21243445005 is 50054434212.

It is not a de Polignac number, because 21243445005 - 2¹² = 21243440909 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243445009) 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 in 15 ways as a sum of consecutive naturals, for example, 17270479 + ... + 17271708.

It is an arithmetic number, because the mean of its divisors is an integer number (2176157844).

Almost surely, 2^21243445005 is an apocalyptic number.

It is an amenable number.

21243445005 is a deficient number, since it is larger than the sum of its proper divisors (13575080499).

21243445005 is a wasteful number, since it uses less digits than its factorization.

21243445005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34542236.

The product of its (nonzero) digits is 19200, while the sum is 30.

Adding to 21243445005 its reverse (50054434212), we get a palindrome (71297879217).

The spelling of 21243445005 in words is "twenty-one billion, two hundred forty-three million, four hundred forty-five thousand, five".