21224365 has 8 divisors (see below), whose sum is σ = 25901280. Its totient is φ = 16691472.

The previous prime is 21224353. The next prime is 21224389. The reversal of 21224365 is 56342212.

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

It is a cyclic number.

It is not a de Polignac number, because 21224365 - 2¹⁹ = 20700077 is a prime.

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, 35679 + ... + 36268.

It is an arithmetic number, because the mean of its divisors is an integer number (3237660).

Almost surely, 2^21224365 is an apocalyptic number.

It is an amenable number.

21224365 is a deficient number, since it is larger than the sum of its proper divisors (4676915).

21224365 is an equidigital number, since it uses as much as digits as its factorization.

21224365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72011.

The product of its digits is 2880, while the sum is 25.

The square root of 21224365 is about 4606.9908834292. The cubic root of 21224365 is about 276.8714883027.

Adding to 21224365 its reverse (56342212), we get a palindrome (77566577).

The spelling of 21224365 in words is "twenty-one million, two hundred twenty-four thousand, three hundred sixty-five".