21224411 has 4 divisors (see below), whose sum is σ = 22857072. Its totient is φ = 19591752.

The previous prime is 21224389. The next prime is 21224431. The reversal of 21224411 is 11442212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21224411 - 2¹⁰ = 21223387 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21224411.

It is not an unprimeable number, because it can be changed into a prime (21224431) 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, 816311 + ... + 816336.

It is an arithmetic number, because the mean of its divisors is an integer number (5714268).

Almost surely, 2^21224411 is an apocalyptic number.

21224411 is a deficient number, since it is larger than the sum of its proper divisors (1632661).

21224411 is a wasteful number, since it uses less digits than its factorization.

21224411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1632660.

The product of its digits is 128, while the sum is 17.

The square root of 21224411 is about 4606.9958758393. The cubic root of 21224411 is about 276.8716883257.

Adding to 21224411 its reverse (11442212), we get a palindrome (32666623).

The spelling of 21224411 in words is "twenty-one million, two hundred twenty-four thousand, four hundred eleven".