18421204 has 6 divisors (see below), whose sum is σ = 32237114. Its totient is φ = 9210600.

The previous prime is 18421201. The next prime is 18421237. The reversal of 18421204 is 40212481.

It can be written as a sum of positive squares in only one way, i.e., 12945604 + 5475600 = 3598^2 + 2340^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18421201) by changing a digit.

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 as a sum of consecutive naturals, namely, 2302647 + ... + 2302654.

Almost surely, 2^18421204 is an apocalyptic number.

It is an amenable number.

18421204 is a deficient number, since it is larger than the sum of its proper divisors (13815910).

18421204 is a wasteful number, since it uses less digits than its factorization.

18421204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4605305 (or 4605303 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 22.

The square root of 18421204 is about 4291.9930102459. The cubic root of 18421204 is about 264.1025963342.

Adding to 18421204 its reverse (40212481), we get a palindrome (58633685).

The spelling of 18421204 in words is "eighteen million, four hundred twenty-one thousand, two hundred four".