21226536 has 96 divisors (see below), whose sum is σ = 60933600. Its totient is φ = 6920640.

The previous prime is 21226531. The next prime is 21226547. The reversal of 21226536 is 63562212.

21226536 is a `hidden beast` number, since 2 + 1 + 2 + 2 + 653 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21226531) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 118495 + ... + 118673.

It is an arithmetic number, because the mean of its divisors is an integer number (634725).

Almost surely, 2^21226536 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21226536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30466800).

21226536 is an abundant number, since it is smaller than the sum of its proper divisors (39707064).

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

21226536 is a wasteful number, since it uses less digits than its factorization.

21226536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261 (or 245 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 21226536 is about 4607.2264975796. The cubic root of 21226536 is about 276.8809282005.

Adding to 21226536 its reverse (63562212), we get a palindrome (84788748).

The spelling of 21226536 in words is "twenty-one million, two hundred twenty-six thousand, five hundred thirty-six".