21908044 has 12 divisors (see below), whose sum is σ = 38879568. Its totient is φ = 10799600.

The previous prime is 21908039. The next prime is 21908069. The reversal of 21908044 is 44080912.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 38287 + ... + 38854.

It is an arithmetic number, because the mean of its divisors is an integer number (3239964).

Almost surely, 2^21908044 is an apocalyptic number.

It is an amenable number.

21908044 is a deficient number, since it is larger than the sum of its proper divisors (16971524).

21908044 is a wasteful number, since it uses less digits than its factorization.

21908044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77216 (or 77214 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 21908044 is about 4680.6029526120. The cubic root of 21908044 is about 279.8129873665.

Adding to 21908044 its reverse (44080912), we get a palindrome (65988956).

The spelling of 21908044 in words is "twenty-one million, nine hundred eight thousand, forty-four".