21223984 has 10 divisors (see below), whose sum is σ = 41121500. Its totient is φ = 10611984.

The previous prime is 21223981. The next prime is 21223997. The reversal of 21223984 is 48932212.

It is not an unprimeable number, because it can be changed into a prime (21223981) 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 as a sum of consecutive naturals, namely, 663234 + ... + 663265.

It is an arithmetic number, because the mean of its divisors is an integer number (4112150).

Almost surely, 2^21223984 is an apocalyptic number.

It is an amenable number.

21223984 is a deficient number, since it is larger than the sum of its proper divisors (19897516).

21223984 is a wasteful number, since it uses less digits than its factorization.

21223984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1326507 (or 1326501 counting only the distinct ones).

The product of its digits is 6912, while the sum is 31.

The square root of 21223984 is about 4606.9495330424. The cubic root of 21223984 is about 276.8698315799.

The spelling of 21223984 in words is "twenty-one million, two hundred twenty-three thousand, nine hundred eighty-four".