21144055 has 16 divisors (see below), whose sum is σ = 26928000. Its totient is φ = 15893280.

The previous prime is 21144049. The next prime is 21144059. The reversal of 21144055 is 55044112.

It is not a de Polignac number, because 21144055 - 2¹⁵ = 21111287 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21144059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11596 + ... + 13294.

It is an arithmetic number, because the mean of its divisors is an integer number (1683000).

Almost surely, 2^21144055 is an apocalyptic number.

21144055 is a deficient number, since it is larger than the sum of its proper divisors (5783945).

21144055 is a wasteful number, since it uses less digits than its factorization.

21144055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1854.

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 21144055 is about 4598.2665212012. The cubic root of 21144055 is about 276.5218327108.

Adding to 21144055 its reverse (55044112), we get a palindrome (76188167).

The spelling of 21144055 in words is "twenty-one million, one hundred forty-four thousand, fifty-five".