21234432 has 72 divisors (see below), whose sum is σ = 57918784. Its totient is φ = 6902784.

The previous prime is 21234431. The next prime is 21234443. The reversal of 21234432 is 23443212.

It is a super-2 number, since 2×21234432² = 901802204725248, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 21234399 and 21234408.

It is not an unprimeable number, because it can be changed into a prime (21234431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32703 + ... + 33345.

Almost surely, 2^21234432 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 21234432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28959392).

21234432 is an abundant number, since it is smaller than the sum of its proper divisors (36684352).

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

21234432 is an equidigital number, since it uses as much as digits as its factorization.

21234432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 705 (or 691 counting only the distinct ones).

The product of its digits is 1152, while the sum is 21.

The square root of 21234432 is about 4608.0833325798. The cubic root of 21234432 is about 276.9152559994.

Adding to 21234432 its reverse (23443212), we get a palindrome (44677644).

It can be divided in two parts, 2123 and 4432, that added together give a triangular number (6555 = T₁₁₄).

The spelling of 21234432 in words is "twenty-one million, two hundred thirty-four thousand, four hundred thirty-two".