18221023204 has 6 divisors (see below), whose sum is σ = 31886790614. Its totient is φ = 9110511600.

The previous prime is 18221023193. The next prime is 18221023207. The reversal of 18221023204 is 40232012281.

It can be written as a sum of positive squares in only one way, i.e., 9110702500 + 9110320704 = 95450^2 + 95448^2 .

It is not an unprimeable number, because it can be changed into a prime (18221023207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2277627897 + ... + 2277627904.

Almost surely, 2^18221023204 is an apocalyptic number.

It is an amenable number.

18221023204 is a deficient number, since it is larger than the sum of its proper divisors (13665767410).

18221023204 is a wasteful number, since it uses less digits than its factorization.

18221023204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4555255805 (or 4555255803 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 25.

Adding to 18221023204 its reverse (40232012281), we get a palindrome (58453035485).

The spelling of 18221023204 in words is "eighteen billion, two hundred twenty-one million, twenty-three thousand, two hundred four".