18221203 has 32 divisors (see below), whose sum is σ = 24837120. Its totient is φ = 12908160.

The previous prime is 18221173. The next prime is 18221213. The reversal of 18221203 is 30212281.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18221203 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18221213) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 109026 + ... + 109192.

It is an arithmetic number, because the mean of its divisors is an integer number (776160).

Almost surely, 2^18221203 is an apocalyptic number.

18221203 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

18221203 is a deficient number, since it is larger than the sum of its proper divisors (6615917).

18221203 is a wasteful number, since it uses less digits than its factorization.

18221203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 18221203 is about 4268.6301081260. The cubic root of 18221203 is about 263.1433194573.

Adding to 18221203 its reverse (30212281), we get a palindrome (48433484).

It can be divided in two parts, 1822 and 1203, that added together give a square (3025 = 55²).

The spelling of 18221203 in words is "eighteen million, two hundred twenty-one thousand, two hundred three".