21559224 has 32 divisors (see below), whose sum is σ = 56736000. Its totient is φ = 6808032.

The previous prime is 21559201. The next prime is 21559259. The reversal of 21559224 is 42295512.

It is a junction number, because it is equal to n+sod(n) for n = 21559191 and 21559200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23184 + ... + 24095.

It is an arithmetic number, because the mean of its divisors is an integer number (1773000).

Almost surely, 2^21559224 is an apocalyptic number.

21559224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21559224 is an abundant number, since it is smaller than the sum of its proper divisors (35176776).

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

21559224 is a wasteful number, since it uses less digits than its factorization.

21559224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47307 (or 47303 counting only the distinct ones).

The product of its digits is 7200, while the sum is 30.

The square root of 21559224 is about 4643.1911440301. The cubic root of 21559224 is about 278.3199738609.

It can be divided in two parts, 2155922 and 4, that added together give a triangular number (2155926 = T₂₀₇₆).

The spelling of 21559224 in words is "twenty-one million, five hundred fifty-nine thousand, two hundred twenty-four".