21043342 has 4 divisors (see below), whose sum is σ = 31565016. Its totient is φ = 10521670.

The previous prime is 21043339. The next prime is 21043381. The reversal of 21043342 is 24334012.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5260834 + ... + 5260837.

It is an arithmetic number, because the mean of its divisors is an integer number (7891254).

Almost surely, 2^21043342 is an apocalyptic number.

21043342 is a deficient number, since it is larger than the sum of its proper divisors (10521674).

21043342 is a wasteful number, since it uses less digits than its factorization.

21043342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10521673.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 21043342 is about 4587.3022573186. The cubic root of 21043342 is about 276.0820924325.

Adding to 21043342 its reverse (24334012), we get a palindrome (45377354).

The spelling of 21043342 in words is "twenty-one million, forty-three thousand, three hundred forty-two".