18122403 has 16 divisors (see below), whose sum is σ = 26216960. Its totient is φ = 11068704.

The previous prime is 18122399. The next prime is 18122431. The reversal of 18122403 is 30422181.

It is not a de Polignac number, because 18122403 - 2² = 18122399 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18122403.

It is not an unprimeable number, because it can be changed into a prime (18122453) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3750 + ... + 7092.

It is an arithmetic number, because the mean of its divisors is an integer number (1638560).

Almost surely, 2^18122403 is an apocalyptic number.

18122403 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

18122403 is a deficient number, since it is larger than the sum of its proper divisors (8094557).

18122403 is a wasteful number, since it uses less digits than its factorization.

18122403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3498.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 18122403 is about 4257.0415783734. The cubic root of 18122403 is about 262.6668472160. Note that the first 3 decimals are identical.

Adding to 18122403 its reverse (30422181), we get a palindrome (48544584).

The spelling of 18122403 in words is "eighteen million, one hundred twenty-two thousand, four hundred three".