21423712 has 24 divisors (see below), whose sum is σ = 42284592. Its totient is φ = 10684800.

The previous prime is 21423709. The next prime is 21423751. The reversal of 21423712 is 21732412.

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, 19662 + ... + 20722.

It is an arithmetic number, because the mean of its divisors is an integer number (1761858).

Almost surely, 2^21423712 is an apocalyptic number.

It is an amenable number.

21423712 is a deficient number, since it is larger than the sum of its proper divisors (20860880).

21423712 is a wasteful number, since it uses less digits than its factorization.

21423712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1702 (or 1694 counting only the distinct ones).

The product of its digits is 672, while the sum is 22.

The square root of 21423712 is about 4628.5755908271. The cubic root of 21423712 is about 277.7356146257.

The spelling of 21423712 in words is "twenty-one million, four hundred twenty-three thousand, seven hundred twelve".