21224109 has 8 divisors (see below), whose sum is σ = 29963520. Its totient is φ = 13317056.

The previous prime is 21224087. The next prime is 21224123. The reversal of 21224109 is 90142212.

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 21224109 - 2⁷ = 21223981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21224149) 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, 208029 + ... + 208130.

It is an arithmetic number, because the mean of its divisors is an integer number (3745440).

Almost surely, 2^21224109 is an apocalyptic number.

It is an amenable number.

21224109 is a deficient number, since it is larger than the sum of its proper divisors (8739411).

21224109 is a wasteful number, since it uses less digits than its factorization.

21224109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416179.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21224109 is about 4606.9630994832. The cubic root of 21224109 is about 276.8703751264.

The spelling of 21224109 in words is "twenty-one million, two hundred twenty-four thousand, one hundred nine".