21563234 has 48 divisors (see below), whose sum is σ = 41713056. Its totient is φ = 8265600.

The previous prime is 21563219. The next prime is 21563237. The reversal of 21563234 is 43236512.

21563234 is a modest number, since divided by 3234 gives 2156 as remainder.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21563237) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 89354 + ... + 89594.

It is an arithmetic number, because the mean of its divisors is an integer number (869022).

Almost surely, 2^21563234 is an apocalyptic number.

21563234 is a deficient number, since it is larger than the sum of its proper divisors (20149822).

21563234 is a wasteful number, since it uses less digits than its factorization.

21563234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351 (or 344 counting only the distinct ones).

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

The square root of 21563234 is about 4643.6229390423. The cubic root of 21563234 is about 278.3372285621.

Adding to 21563234 its reverse (43236512), we get a palindrome (64799746).

The spelling of 21563234 in words is "twenty-one million, five hundred sixty-three thousand, two hundred thirty-four".