21563432 has 16 divisors (see below), whose sum is σ = 44107200. Its totient is φ = 9801520.

The previous prime is 21563419. The next prime is 21563449. The reversal of 21563432 is 23436512.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122432 + ... + 122607.

It is an arithmetic number, because the mean of its divisors is an integer number (2756700).

Almost surely, 2^21563432 is an apocalyptic number.

21563432 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21563432 is an abundant number, since it is smaller than the sum of its proper divisors (22543768).

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

21563432 is a wasteful number, since it uses less digits than its factorization.

21563432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245056 (or 245052 counting only the distinct ones).

The product of its digits is 4320, while the sum is 26.

The square root of 21563432 is about 4643.6442585538. The cubic root of 21563432 is about 278.3380804844.

Adding to 21563432 its reverse (23436512), we get a palindrome (44999944).

Subtracting 21563432 from its reverse (23436512), we obtain a triangular number (1873080 = T₁₉₃₅).

The spelling of 21563432 in words is "twenty-one million, five hundred sixty-three thousand, four hundred thirty-two".