21201110255 has 16 divisors (see below), whose sum is σ = 27441154944. Its totient is φ = 15631749120.

The previous prime is 21201110251. The next prime is 21201110257. The reversal of 21201110255 is 55201110212.

It is not a de Polignac number, because 21201110255 - 2² = 21201110251 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201110251) 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, 212759 + ... + 296088.

It is an arithmetic number, because the mean of its divisors is an integer number (1715072184).

Almost surely, 2^21201110255 is an apocalyptic number.

21201110255 is a deficient number, since it is larger than the sum of its proper divisors (6240044689).

21201110255 is a wasteful number, since it uses less digits than its factorization.

21201110255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509506.

The product of its (nonzero) digits is 200, while the sum is 20.

Adding to 21201110255 its reverse (55201110212), we get a palindrome (76402220467).

The spelling of 21201110255 in words is "twenty-one billion, two hundred one million, one hundred ten thousand, two hundred fifty-five".