21444100203205 has 16 divisors (see below), whose sum is σ = 26629509196800. Its totient is φ = 16557965166400.

The previous prime is 21444100203191. The next prime is 21444100203209. The reversal of 21444100203205 is 50230200144412.

It is not a de Polignac number, because 21444100203205 - 2⁵ = 21444100203173 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444100203209) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 25266871 + ... + 26101780.

It is an arithmetic number, because the mean of its divisors is an integer number (1664344324800).

Almost surely, 2^{21444100203205} is an apocalyptic number.

It is an amenable number.

21444100203205 is a deficient number, since it is larger than the sum of its proper divisors (5185408993595).

21444100203205 is a wasteful number, since it uses less digits than its factorization.

21444100203205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51371564.

The product of its (nonzero) digits is 7680, while the sum is 28.

Adding to 21444100203205 its reverse (50230200144412), we get a palindrome (71674300347617).

The spelling of 21444100203205 in words is "twenty-one trillion, four hundred forty-four billion, one hundred million, two hundred three thousand, two hundred five".