21544345219 has 4 divisors (see below), whose sum is σ = 21565614096. Its totient is φ = 21523076344.

The previous prime is 21544345201. The next prime is 21544345223. The reversal of 21544345219 is 91254344512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21544345219 - 2⁹ = 21544344707 is a prime.

It is a super-2 number, since 2×21544345219² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21544345289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10632919 + ... + 10634944.

It is an arithmetic number, because the mean of its divisors is an integer number (5391403524).

Almost surely, 2^21544345219 is an apocalyptic number.

21544345219 is a deficient number, since it is larger than the sum of its proper divisors (21268877).

21544345219 is a wasteful number, since it uses less digits than its factorization.

21544345219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21268876.

The product of its digits is 172800, while the sum is 40.

The spelling of 21544345219 in words is "twenty-one billion, five hundred forty-four million, three hundred forty-five thousand, two hundred nineteen".