21227536 has 40 divisors (see below), whose sum is σ = 46425600. Its totient is φ = 9313920.

The previous prime is 21227533. The next prime is 21227561. The reversal of 21227536 is 63572212.

It is not an unprimeable number, because it can be changed into a prime (21227533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3025 + ... + 7183.

It is an arithmetic number, because the mean of its divisors is an integer number (1160640).

Almost surely, 2^21227536 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 21227536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23212800).

21227536 is an abundant number, since it is smaller than the sum of its proper divisors (25198064).

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

21227536 is a wasteful number, since it uses less digits than its factorization.

21227536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4207 (or 4201 counting only the distinct ones).

The product of its digits is 5040, while the sum is 28.

The square root of 21227536 is about 4607.3350214631. The cubic root of 21227536 is about 276.8852761635.

Adding to 21227536 its reverse (63572212), we get a palindrome (84799748).

The spelling of 21227536 in words is "twenty-one million, two hundred twenty-seven thousand, five hundred thirty-six".