21424266 has 12 divisors (see below), whose sum is σ = 46419282. Its totient is φ = 7141416.

The previous prime is 21424261. The next prime is 21424297. The reversal of 21424266 is 66242412.

It can be written as a sum of positive squares in only one way, i.e., 15563025 + 5861241 = 3945^2 + 2421^2 .

It is not an unprimeable number, because it can be changed into a prime (21424261) 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 5 ways as a sum of consecutive naturals, for example, 595101 + ... + 595136.

Almost surely, 2^21424266 is an apocalyptic number.

21424266 is an abundant number, since it is smaller than the sum of its proper divisors (24995016).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21424266 is a wasteful number, since it uses less digits than its factorization.

21424266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1190245 (or 1190242 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

The square root of 21424266 is about 4628.6354360654. The cubic root of 21424266 is about 277.7380086117.

Adding to 21424266 its reverse (66242412), we get a palindrome (87666678).

The spelling of 21424266 in words is "twenty-one million, four hundred twenty-four thousand, two hundred sixty-six".