21144340055 has 32 divisors (see below), whose sum is σ = 26505964800. Its totient is φ = 16181966592.

The previous prime is 21144340043. The next prime is 21144340069. The reversal of 21144340055 is 55004344112.

It is a cyclic number.

It is not a de Polignac number, because 21144340055 - 2¹⁴ = 21144323671 is a prime.

It is a super-2 number, since 2×21144340055² (a number of 21 digits) contains 22 as substring.

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 31 ways as a sum of consecutive naturals, for example, 1634051 + ... + 1646939.

It is an arithmetic number, because the mean of its divisors is an integer number (828311400).

Almost surely, 2^21144340055 is an apocalyptic number.

21144340055 is a deficient number, since it is larger than the sum of its proper divisors (5361624745).

21144340055 is a wasteful number, since it uses less digits than its factorization.

21144340055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13103.

The product of its (nonzero) digits is 9600, while the sum is 29.

Adding to 21144340055 its reverse (55004344112), we get a palindrome (76148684167).

The spelling of 21144340055 in words is "twenty-one billion, one hundred forty-four million, three hundred forty thousand, fifty-five".