21223305 has 24 divisors (see below), whose sum is σ = 36953280. Its totient is φ = 11268000.

The previous prime is 21223297. The next prime is 21223333. The reversal of 21223305 is 50332212.

It is not a de Polignac number, because 21223305 - 2³ = 21223297 is a prime.

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 23 ways as a sum of consecutive naturals, for example, 10356 + ... + 12234.

It is an arithmetic number, because the mean of its divisors is an integer number (1539720).

Almost surely, 2^21223305 is an apocalyptic number.

It is an amenable number.

21223305 is a deficient number, since it is larger than the sum of its proper divisors (15729975).

21223305 is a wasteful number, since it uses less digits than its factorization.

21223305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2141 (or 2138 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 21223305 is about 4606.8758394383. The cubic root of 21223305 is about 276.8668789986.

Adding to 21223305 its reverse (50332212), we get a palindrome (71555517).

It can be divided in two parts, 21223 and 305, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 21223305 in words is "twenty-one million, two hundred twenty-three thousand, three hundred five".