21493343 has 4 divisors (see below), whose sum is σ = 21625368. Its totient is φ = 21361320.

The previous prime is 21493331. The next prime is 21493349. The reversal of 21493343 is 34339412.

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

It is a cyclic number.

It is not a de Polignac number, because 21493343 - 2⁶ = 21493279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21493349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65768 + ... + 66093.

It is an arithmetic number, because the mean of its divisors is an integer number (5406342).

Almost surely, 2^21493343 is an apocalyptic number.

21493343 is a deficient number, since it is larger than the sum of its proper divisors (132025).

21493343 is a wasteful number, since it uses less digits than its factorization.

21493343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132024.

The product of its digits is 7776, while the sum is 29.

The square root of 21493343 is about 4636.0913494020. The cubic root of 21493343 is about 278.0361864804.

The spelling of 21493343 in words is "twenty-one million, four hundred ninety-three thousand, three hundred forty-three".