21224361 has 8 divisors (see below), whose sum is σ = 28366240. Its totient is φ = 14116032.

The previous prime is 21224353. The next prime is 21224389. The reversal of 21224361 is 16342212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21224361 - 2³ = 21224353 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21224321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6871 + ... + 9468.

It is an arithmetic number, because the mean of its divisors is an integer number (3545780).

Almost surely, 2^21224361 is an apocalyptic number.

It is an amenable number.

21224361 is a deficient number, since it is larger than the sum of its proper divisors (7141879).

21224361 is a wasteful number, since it uses less digits than its factorization.

21224361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16775.

The product of its digits is 576, while the sum is 21.

The square root of 21224361 is about 4606.9904493064. The cubic root of 21224361 is about 276.8714709094.

Adding to 21224361 its reverse (16342212), we get a palindrome (37566573).

The spelling of 21224361 in words is "twenty-one million, two hundred twenty-four thousand, three hundred sixty-one".