21044871 has 12 divisors (see below), whose sum is σ = 30533880. Its totient is φ = 13967280.

The previous prime is 21044833. The next prime is 21044873. The reversal of 21044871 is 17844012.

21044871 is a `hidden beast` number, since 210 + 448 + 7 + 1 = 666.

It is not a de Polignac number, because 21044871 - 2⁷ = 21044743 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21044873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3045 + ... + 7166.

It is an arithmetic number, because the mean of its divisors is an integer number (2544490).

Almost surely, 2^21044871 is an apocalyptic number.

21044871 is a deficient number, since it is larger than the sum of its proper divisors (9489009).

21044871 is a wasteful number, since it uses less digits than its factorization.

21044871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10446 (or 10443 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 21044871 is about 4587.4689099764. The cubic root of 21044871 is about 276.0887789385.

Adding to 21044871 its reverse (17844012), we get a palindrome (38888883).

The spelling of 21044871 in words is "twenty-one million, forty-four thousand, eight hundred seventy-one".