21224313 has 24 divisors (see below), whose sum is σ = 35414496. Its totient is φ = 12105600.

The previous prime is 21224297. The next prime is 21224321. The reversal of 21224313 is 31342212.

It is not a de Polignac number, because 21224313 - 2⁴ = 21224297 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21224323) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4623 + ... + 7988.

It is an arithmetic number, because the mean of its divisors is an integer number (1475604).

Almost surely, 2^21224313 is an apocalyptic number.

It is an amenable number.

21224313 is a deficient number, since it is larger than the sum of its proper divisors (14190183).

21224313 is a wasteful number, since it uses less digits than its factorization.

21224313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12645 (or 12642 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 21224313 is about 4606.9852398288. The cubic root of 21224313 is about 276.8712621895.

Adding to 21224313 its reverse (31342212), we get a palindrome (52566525).

The spelling of 21224313 in words is "twenty-one million, two hundred twenty-four thousand, three hundred thirteen".