21144340044 has 18 divisors (see below), whose sum is σ = 53448192980. Its totient is φ = 7048113336.

The previous prime is 21144340043. The next prime is 21144340069. The reversal of 21144340044 is 44004344112.

21144340044 is a `hidden beast` number, since 211 + 4 + 4 + 3 + 400 + 44 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is not an unprimeable number, because it can be changed into a prime (21144340043) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 293671354 + ... + 293671425.

Almost surely, 2^21144340044 is an apocalyptic number.

It is an amenable number.

21144340044 is an abundant number, since it is smaller than the sum of its proper divisors (32303852936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21144340044 is a wasteful number, since it uses less digits than its factorization.

21144340044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 587342789 (or 587342784 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 27.

Adding to 21144340044 its reverse (44004344112), we get a palindrome (65148684156).

The spelling of 21144340044 in words is "twenty-one billion, one hundred forty-four million, three hundred forty thousand, forty-four".