21608042 has 8 divisors (see below), whose sum is σ = 32961600. Its totient is φ = 10620844.

The previous prime is 21608039. The next prime is 21608077. The reversal of 21608042 is 24080612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21607999 and 21608017.

It is an unprimeable number.

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, 91442 + ... + 91677.

It is an arithmetic number, because the mean of its divisors is an integer number (4120200).

Almost surely, 2^21608042 is an apocalyptic number.

21608042 is a deficient number, since it is larger than the sum of its proper divisors (11353558).

21608042 is a wasteful number, since it uses less digits than its factorization.

21608042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183180.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 21608042 is about 4648.4451163803. The cubic root of 21608042 is about 278.5298883740.

Adding to 21608042 its reverse (24080612), we get a palindrome (45688654).

The spelling of 21608042 in words is "twenty-one million, six hundred eight thousand, forty-two".