21044200055 has 4 divisors (see below), whose sum is σ = 25253040072. Its totient is φ = 16835360040.

The previous prime is 21044200033. The next prime is 21044200103. The reversal of 21044200055 is 55000244012.

It is a happy number.

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

It is not a de Polignac number, because 21044200055 - 2¹⁸ = 21043937911 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21044200055.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2104420001 + ... + 2104420010.

It is an arithmetic number, because the mean of its divisors is an integer number (6313260018).

Almost surely, 2^21044200055 is an apocalyptic number.

21044200055 is a deficient number, since it is larger than the sum of its proper divisors (4208840017).

21044200055 is an equidigital number, since it uses as much as digits as its factorization.

21044200055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4208840016.

The product of its (nonzero) digits is 1600, while the sum is 23.

Adding to 21044200055 its reverse (55000244012), we get a palindrome (76044444067).

The spelling of 21044200055 in words is "twenty-one billion, forty-four million, two hundred thousand, fifty-five".