21323668 has 12 divisors (see below), whose sum is σ = 38939040. Its totient is φ = 10198232.

The previous prime is 21323663. The next prime is 21323669. The reversal of 21323668 is 86632312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115798 + ... + 115981.

It is an arithmetic number, because the mean of its divisors is an integer number (3244920).

Almost surely, 2^21323668 is an apocalyptic number.

It is an amenable number.

21323668 is a deficient number, since it is larger than the sum of its proper divisors (17615372).

21323668 is a wasteful number, since it uses less digits than its factorization.

21323668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231806 (or 231804 counting only the distinct ones).

The product of its digits is 10368, while the sum is 31.

The square root of 21323668 is about 4617.7557319546. The cubic root of 21323668 is about 277.3026186142.

The spelling of 21323668 in words is "twenty-one million, three hundred twenty-three thousand, six hundred sixty-eight".