21144211055 has 16 divisors (see below), whose sum is σ = 27683251200. Its totient is φ = 15375632160.

The previous prime is 21144211051. The next prime is 21144211063. The reversal of 21144211055 is 55011244112.

It is a happy number.

It is not a de Polignac number, because 21144211055 - 2² = 21144211051 is a prime.

It is a super-2 number, since 2×21144211055² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21144211051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 512486 + ... + 552204.

It is an arithmetic number, because the mean of its divisors is an integer number (1730203200).

Almost surely, 2^21144211055 is an apocalyptic number.

21144211055 is a deficient number, since it is larger than the sum of its proper divisors (6539040145).

21144211055 is a wasteful number, since it uses less digits than its factorization.

21144211055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49414.

The product of its (nonzero) digits is 1600, while the sum is 26.

Adding to 21144211055 its reverse (55011244112), we get a palindrome (76155455167).

The spelling of 21144211055 in words is "twenty-one billion, one hundred forty-four million, two hundred eleven thousand, fifty-five".