21544330412205 has 96 divisors (see below), whose sum is σ = 38875133606400. Its totient is φ = 11446304348160.

The previous prime is 21544330412197. The next prime is 21544330412239. The reversal of 21544330412205 is 50221403344512.

It is a happy number.

21544330412205 is a `hidden beast` number, since 2 + 1 + 5 + 4 + 4 + 3 + 30 + 412 + 205 = 666.

It is not a de Polignac number, because 21544330412205 - 2³ = 21544330412197 is a prime.

It is a super-2 number, since 2×21544330412205² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21544330412205.

It is a congruent number.

It is an unprimeable number.

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 95 ways as a sum of consecutive naturals, for example, 437877196 + ... + 437926394.

It is an arithmetic number, because the mean of its divisors is an integer number (404949308400).

Almost surely, 2^{21544330412205} is an apocalyptic number.

It is an amenable number.

21544330412205 is a deficient number, since it is larger than the sum of its proper divisors (17330803194195).

21544330412205 is a wasteful number, since it uses less digits than its factorization.

21544330412205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50593 (or 50581 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 36.

Adding to 21544330412205 its reverse (50221403344512), we get a palindrome (71765733756717).

The spelling of 21544330412205 in words is "twenty-one trillion, five hundred forty-four billion, three hundred thirty million, four hundred twelve thousand, two hundred five".