21344242 has 4 divisors (see below), whose sum is σ = 32016366. Its totient is φ = 10672120.

The previous prime is 21344237. The next prime is 21344243. The reversal of 21344242 is 24244312.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 12047841 + 9296401 = 3471^2 + 3049^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21344243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5336059 + ... + 5336062.

Almost surely, 2^21344242 is an apocalyptic number.

21344242 is a deficient number, since it is larger than the sum of its proper divisors (10672124).

21344242 is a wasteful number, since it uses less digits than its factorization.

21344242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10672123.

The product of its digits is 1536, while the sum is 22.

The square root of 21344242 is about 4619.9829004013. The cubic root of 21344242 is about 277.3917744789.

Adding to 21344242 its reverse (24244312), we get a palindrome (45588554).

The spelling of 21344242 in words is "twenty-one million, three hundred forty-four thousand, two hundred forty-two".