18421224 has 16 divisors (see below), whose sum is σ = 46053120. Its totient is φ = 6140400.

The previous prime is 18421201. The next prime is 18421237. The reversal of 18421224 is 42212481.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 767551 = 18421224 / (1 + 8 + 4 + 2 + 1 + 2 + 2 + 4).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 18421194 and 18421203.

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 3 ways as a sum of consecutive naturals, for example, 383752 + ... + 383799.

It is an arithmetic number, because the mean of its divisors is an integer number (2878320).

Almost surely, 2^18421224 is an apocalyptic number.

It is an amenable number.

18421224 is an abundant number, since it is smaller than the sum of its proper divisors (27631896).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18421224 is a wasteful number, since it uses less digits than its factorization.

18421224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 767560 (or 767556 counting only the distinct ones).

The product of its digits is 1024, while the sum is 24.

The square root of 18421224 is about 4291.9953401652. The cubic root of 18421224 is about 264.1026919134.

The spelling of 18421224 in words is "eighteen million, four hundred twenty-one thousand, two hundred twenty-four".