21544435412055 has 96 divisors (see below), whose sum is σ = 37617049596672. Its totient is φ = 11406624768000.

The previous prime is 21544435412039. The next prime is 21544435412083. The reversal of 21544435412055 is 55021453444512.

21544435412055 is a `hidden beast` number, since 2 + 1 + 5 + 4 + 4 + 435 + 4 + 1 + 205 + 5 = 666.

It is not a de Polignac number, because 21544435412055 - 2⁴ = 21544435412039 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21544435412055.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9163944130 + ... + 9163946480.

It is an arithmetic number, because the mean of its divisors is an integer number (391844266632).

Almost surely, 2^{21544435412055} is an apocalyptic number.

21544435412055 is a deficient number, since it is larger than the sum of its proper divisors (16072614184617).

21544435412055 is a wasteful number, since it uses less digits than its factorization.

21544435412055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5049 (or 5046 counting only the distinct ones).

The product of its (nonzero) digits is 1920000, while the sum is 45.

Adding to 21544435412055 its reverse (55021453444512), we get a palindrome (76565888856567).

The spelling of 21544435412055 in words is "twenty-one trillion, five hundred forty-four billion, four hundred thirty-five million, four hundred twelve thousand, fifty-five".