21142304 has 24 divisors (see below), whose sum is σ = 41731200. Its totient is φ = 10543936.

The previous prime is 21142291. The next prime is 21142343. The reversal of 21142304 is 40324112.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18617 + ... + 19719.

It is an arithmetic number, because the mean of its divisors is an integer number (1738800).

Almost surely, 2^21142304 is an apocalyptic number.

It is an amenable number.

21142304 is a deficient number, since it is larger than the sum of its proper divisors (20588896).

21142304 is a wasteful number, since it uses less digits than its factorization.

21142304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1712 (or 1704 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21142304 is about 4598.0761194221. The cubic root of 21142304 is about 276.5141993107.

Adding to 21142304 its reverse (40324112), we get a palindrome (61466416).

The spelling of 21142304 in words is "twenty-one million, one hundred forty-two thousand, three hundred four".