21323224 has 16 divisors (see below), whose sum is σ = 43056720.
Its totient is φ = 9841440.
The previous prime is 21323209. The next prime is 21323261. The reversal of 21323224 is 42232312.
21323224 = 2112 + 2122 + ... + 4182.
It is a congruent number.
It is an unprimeable number.
It is a pernicious number, because its binary representation contains a prime number (13) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102412 + ... + 102619.
It is an arithmetic number, because the mean of its divisors is an integer number (2691045).
Almost surely, 221323224 is an apocalyptic number.
It is an amenable number.
21323224 is an abundant number, since it is smaller than the sum of its proper divisors (21733496).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
21323224 is a wasteful number, since it uses less digits than its factorization.
21323224 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 205050 (or 205046 counting only the distinct ones).
The product of its digits is 576, while the sum is 19.
The square root of 21323224 is about 4617.7076564027.
The cubic root of 21323224 is about 277.3006939419.
Adding to 21323224 its reverse (42232312), we get a palindrome (63555536).
It can be divided in two parts, 2132 and 3224, that added together give a triangular number (5356 = T103).
The spelling of 21323224 in words is "twenty-one million, three hundred twenty-three thousand, two hundred twenty-four".