21109223 has 8 divisors (see below), whose sum is σ = 22667040. Its totient is φ = 19586560.

The previous prime is 21109217. The next prime is 21109229. The reversal of 21109223 is 32290112.

It is an interprime number because it is at equal distance from previous prime (21109217) and next prime (21109229).

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 21109223 - 2⁶ = 21109159 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21109195 and 21109204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21109229) 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, 7538 + ... + 9951.

It is an arithmetic number, because the mean of its divisors is an integer number (2833380).

Almost surely, 2^21109223 is an apocalyptic number.

21109223 is a deficient number, since it is larger than the sum of its proper divisors (1557817).

21109223 is a wasteful number, since it uses less digits than its factorization.

21109223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17577.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 21109223 is about 4594.4774458038. The cubic root of 21109223 is about 276.3699050198.

Adding to 21109223 its reverse (32290112), we get a palindrome (53399335).

The spelling of 21109223 in words is "twenty-one million, one hundred nine thousand, two hundred twenty-three".