21304142 has 8 divisors (see below), whose sum is σ = 31978800. Its totient is φ = 10644544.

The previous prime is 21304139. The next prime is 21304147. The reversal of 21304142 is 24140312.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21304142.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21304147) 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 in 3 ways as a sum of consecutive naturals, for example, 959 + ... + 6597.

It is an arithmetic number, because the mean of its divisors is an integer number (3997350).

Almost surely, 2^21304142 is an apocalyptic number.

21304142 is a deficient number, since it is larger than the sum of its proper divisors (10674658).

21304142 is a wasteful number, since it uses less digits than its factorization.

21304142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7530.

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

The square root of 21304142 is about 4615.6410172369. The cubic root of 21304142 is about 277.2179511220.

Adding to 21304142 its reverse (24140312), we get a palindrome (45444454).

The spelling of 21304142 in words is "twenty-one million, three hundred four thousand, one hundred forty-two".