21544323205 has 8 divisors (see below), whose sum is σ = 26094807072. Its totient is φ = 17074379088.

The previous prime is 21544323179. The next prime is 21544323257. The reversal of 21544323205 is 50232344512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21544323205 - 2¹¹ = 21544321157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20134347 + ... + 20135416.

It is an arithmetic number, because the mean of its divisors is an integer number (3261850884).

Almost surely, 2^21544323205 is an apocalyptic number.

It is an amenable number.

21544323205 is a deficient number, since it is larger than the sum of its proper divisors (4550483867).

21544323205 is a wasteful number, since it uses less digits than its factorization.

21544323205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40269875.

The product of its (nonzero) digits is 28800, while the sum is 31.

Adding to 21544323205 its reverse (50232344512), we get a palindrome (71776667717).

The spelling of 21544323205 in words is "twenty-one billion, five hundred forty-four million, three hundred twenty-three thousand, two hundred five".