21242626 has 16 divisors (see below), whose sum is σ = 33315840. Its totient is φ = 10146240.

The previous prime is 21242591. The next prime is 21242629. The reversal of 21242626 is 62624212.

It is a self number, because there is not a number n which added to its sum of digits gives 21242626.

It is not an unprimeable number, because it can be changed into a prime (21242629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2730 + ... + 7066.

It is an arithmetic number, because the mean of its divisors is an integer number (2082240).

Almost surely, 2^21242626 is an apocalyptic number.

21242626 is a deficient number, since it is larger than the sum of its proper divisors (12073214).

21242626 is a wasteful number, since it uses less digits than its factorization.

21242626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4449.

The product of its digits is 2304, while the sum is 25.

The square root of 21242626 is about 4608.9723366495. The cubic root of 21242626 is about 276.9508703546.

Adding to 21242626 its reverse (62624212), we get a palindrome (83866838).

The spelling of 21242626 in words is "twenty-one million, two hundred forty-two thousand, six hundred twenty-six".