21416242 has 16 divisors (see below), whose sum is σ = 32806872. Its totient is φ = 10483200.

The previous prime is 21416183. The next prime is 21416281. The reversal of 21416242 is 24261412.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 20511841 + 904401 = 4529^2 + 951^2 .

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 19048 + ... + 20140.

Almost surely, 2^21416242 is an apocalyptic number.

21416242 is a deficient number, since it is larger than the sum of its proper divisors (11390630).

21416242 is a wasteful number, since it uses less digits than its factorization.

21416242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1293.

The product of its digits is 768, while the sum is 22.

The square root of 21416242 is about 4627.7685767549. The cubic root of 21416242 is about 277.7033306744.

Adding to 21416242 its reverse (24261412), we get a palindrome (45677654).

The spelling of 21416242 in words is "twenty-one million, four hundred sixteen thousand, two hundred forty-two".