21443668 has 12 divisors (see below), whose sum is σ = 38162880. Its totient is φ = 10539992.

The previous prime is 21443657. The next prime is 21443701. The reversal of 21443668 is 86634412.

It is a congruent number.

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, 45196 + ... + 45667.

It is an arithmetic number, because the mean of its divisors is an integer number (3180240).

Almost surely, 2^21443668 is an apocalyptic number.

It is an amenable number.

21443668 is a deficient number, since it is larger than the sum of its proper divisors (16719212).

21443668 is a wasteful number, since it uses less digits than its factorization.

21443668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90926 (or 90924 counting only the distinct ones).

The product of its digits is 27648, while the sum is 34.

The square root of 21443668 is about 4630.7308278500. The cubic root of 21443668 is about 277.8218239606.

The spelling of 21443668 in words is "twenty-one million, four hundred forty-three thousand, six hundred sixty-eight".