18211204 has 24 divisors (see below), whose sum is σ = 35009856. Its totient is φ = 8220000.

The previous prime is 18211201. The next prime is 18211213. The reversal of 18211204 is 40211281.

It is a happy number.

It is a super-2 number, since 2×18211204² = 663295902259232, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18211201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5274 + ... + 8014.

It is an arithmetic number, because the mean of its divisors is an integer number (1458744).

Almost surely, 2^18211204 is an apocalyptic number.

It is an amenable number.

18211204 is a deficient number, since it is larger than the sum of its proper divisors (16798652).

18211204 is a wasteful number, since it uses less digits than its factorization.

18211204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2907 (or 2905 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 18211204 is about 4267.4587285643. The cubic root of 18211204 is about 263.0951767983.

Adding to 18211204 its reverse (40211281), we get a palindrome (58422485).

It can be divided in two parts, 1821 and 1204, that added together give a square (3025 = 55²).

The spelling of 18211204 in words is "eighteen million, two hundred eleven thousand, two hundred four".