21433536 has 84 divisors (see below), whose sum is σ = 62130432. Its totient is φ = 7064064.

The previous prime is 21433519. The next prime is 21433541. The reversal of 21433536 is 63533412.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 73006 + ... + 73298.

It is an arithmetic number, because the mean of its divisors is an integer number (739648).

Almost surely, 2^21433536 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 21433536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31065216).

21433536 is an abundant number, since it is smaller than the sum of its proper divisors (40696896).

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

21433536 is a wasteful number, since it uses less digits than its factorization.

21433536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438 (or 425 counting only the distinct ones).

The product of its digits is 6480, while the sum is 27.

The square root of 21433536 is about 4629.6367028094. The cubic root of 21433536 is about 277.7780607049.

Adding to 21433536 its reverse (63533412), we get a palindrome (84966948).

The spelling of 21433536 in words is "twenty-one million, four hundred thirty-three thousand, five hundred thirty-six".