18725218 has 16 divisors (see below), whose sum is σ = 28775736. Its totient is φ = 9135360.

The previous prime is 18725207. The next prime is 18725237. The reversal of 18725218 is 81252781.

It can be written as a sum of positive squares in 4 ways, for example, as 18173169 + 552049 = 4263^2 + 743^2 .

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25180 + ... + 25912.

Almost surely, 2^18725218 is an apocalyptic number.

18725218 is a deficient number, since it is larger than the sum of its proper divisors (10050518).

18725218 is a wasteful number, since it uses less digits than its factorization.

18725218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1029.

The product of its digits is 8960, while the sum is 34.

The square root of 18725218 is about 4327.2644938806. The cubic root of 18725218 is about 265.5475471157.

Adding to 18725218 its reverse (81252781), we get a palindrome (99977999).

The spelling of 18725218 in words is "eighteen million, seven hundred twenty-five thousand, two hundred eighteen".