21824218 has 32 divisors (see below), whose sum is σ = 36832320. Its totient is φ = 9632640.

The previous prime is 21824203. The next prime is 21824221. The reversal of 21824218 is 81242812.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62721 + ... + 63067.

It is an arithmetic number, because the mean of its divisors is an integer number (1151010).

Almost surely, 2^21824218 is an apocalyptic number.

21824218 is a deficient number, since it is larger than the sum of its proper divisors (15008102).

21824218 is a wasteful number, since it uses less digits than its factorization.

21824218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462.

The product of its digits is 2048, while the sum is 28.

The square root of 21824218 is about 4671.6397549469. The cubic root of 21824218 is about 279.4556516010.

It can be divided in two parts, 2182 and 4218, that added together give a square (6400 = 80²).

The spelling of 21824218 in words is "twenty-one million, eight hundred twenty-four thousand, two hundred eighteen".