21433236 has 48 divisors (see below), whose sum is σ = 54828480. Its totient is φ = 6462720.

The previous prime is 21433231. The next prime is 21433259. The reversal of 21433236 is 63233412.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21433231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52200 + ... + 52608.

It is an arithmetic number, because the mean of its divisors is an integer number (1142260).

Almost surely, 2^21433236 is an apocalyptic number.

It is an amenable number.

21433236 is an abundant number, since it is smaller than the sum of its proper divisors (33395244).

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

21433236 is a wasteful number, since it uses less digits than its factorization.

21433236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 824 (or 822 counting only the distinct ones).

The product of its digits is 2592, while the sum is 24.

The square root of 21433236 is about 4629.6043027455. The cubic root of 21433236 is about 277.7767647015.

Adding to 21433236 its reverse (63233412), we get a palindrome (84666648).

The spelling of 21433236 in words is "twenty-one million, four hundred thirty-three thousand, two hundred thirty-six".