21241536 has 56 divisors (see below), whose sum is σ = 56540400. Its totient is φ = 7037952.

The previous prime is 21241531. The next prime is 21241553. The reversal of 21241536 is 63514212.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (21241531) 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, 60690 + ... + 61038.

It is an arithmetic number, because the mean of its divisors is an integer number (1009650).

Almost surely, 2^21241536 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 21241536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28270200).

21241536 is an abundant number, since it is smaller than the sum of its proper divisors (35298864).

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

21241536 is a wasteful number, since it uses less digits than its factorization.

21241536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681 (or 671 counting only the distinct ones).

The product of its digits is 1440, while the sum is 24.

The square root of 21241536 is about 4608.8540875146. The cubic root of 21241536 is about 276.9461333130.

Adding to 21241536 its reverse (63514212), we get a palindrome (84755748).

The spelling of 21241536 in words is "twenty-one million, two hundred forty-one thousand, five hundred thirty-six".