21223235 has 8 divisors (see below), whose sum is σ = 27783216. Its totient is φ = 15435040.

The previous prime is 21223219. The next prime is 21223261. The reversal of 21223235 is 53232212.

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

It is not a de Polignac number, because 21223235 - 2⁴ = 21223219 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 192884 + ... + 192993.

It is an arithmetic number, because the mean of its divisors is an integer number (3472902).

Almost surely, 2^21223235 is an apocalyptic number.

21223235 is a deficient number, since it is larger than the sum of its proper divisors (6559981).

21223235 is a wasteful number, since it uses less digits than its factorization.

21223235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385893.

The product of its digits is 720, while the sum is 20.

The square root of 21223235 is about 4606.8682420925. The cubic root of 21223235 is about 276.8665746051.

Adding to 21223235 its reverse (53232212), we get a palindrome (74455447).

The spelling of 21223235 in words is "twenty-one million, two hundred twenty-three thousand, two hundred thirty-five".