21345224 has 16 divisors (see below), whose sum is σ = 40110000. Its totient is φ = 10649232.

The previous prime is 21345223. The next prime is 21345229. The reversal of 21345224 is 42254312.

It is a happy number.

It is a super-3 number, since 3×21345224³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 21345224.

It is not an unprimeable number, because it can be changed into a prime (21345223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1319 + ... + 6665.

It is an arithmetic number, because the mean of its divisors is an integer number (2506875).

Almost surely, 2^21345224 is an apocalyptic number.

It is an amenable number.

21345224 is a deficient number, since it is larger than the sum of its proper divisors (18764776).

21345224 is a wasteful number, since it uses less digits than its factorization.

21345224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5852 (or 5848 counting only the distinct ones).

The product of its digits is 1920, while the sum is 23.

The square root of 21345224 is about 4620.0891766285. The cubic root of 21345224 is about 277.3960284684.

Adding to 21345224 its reverse (42254312), we get a palindrome (63599536).

The spelling of 21345224 in words is "twenty-one million, three hundred forty-five thousand, two hundred twenty-four".