21226436 has 24 divisors (see below), whose sum is σ = 46312896. Its totient is φ = 8269920.

The previous prime is 21226423. The next prime is 21226441. The reversal of 21226436 is 63462212.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34151 + ... + 34766.

It is an arithmetic number, because the mean of its divisors is an integer number (1929704).

Almost surely, 2^21226436 is an apocalyptic number.

It is an amenable number.

21226436 is an abundant number, since it is smaller than the sum of its proper divisors (25086460).

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

21226436 is a wasteful number, since it uses less digits than its factorization.

21226436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68939 (or 68937 counting only the distinct ones).

The product of its digits is 3456, while the sum is 26.

The square root of 21226436 is about 4607.2156450507. The cubic root of 21226436 is about 276.8804933967.

Adding to 21226436 its reverse (63462212), we get a palindrome (84688648).

It can be divided in two parts, 2122 and 6436, that added together give a palindrome (8558).

The spelling of 21226436 in words is "twenty-one million, two hundred twenty-six thousand, four hundred thirty-six".