18128449 has 2 divisors, whose sum is σ = 18128450. Its totient is φ = 18128448.

The previous prime is 18128441. The next prime is 18128471. The reversal of 18128449 is 94482181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18122049 + 6400 = 4257^2 + 80^2 .

It is a cyclic number.

It is not a de Polignac number, because 18128449 - 2³ = 18128441 is a prime.

It is not a weakly prime, because it can be changed into another prime (18128441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9064224 + 9064225.

It is an arithmetic number, because the mean of its divisors is an integer number (9064225).

Almost surely, 2^18128449 is an apocalyptic number.

It is an amenable number.

18128449 is a deficient number, since it is larger than the sum of its proper divisors (1).

18128449 is an equidigital number, since it uses as much as digits as its factorization.

18128449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18432, while the sum is 37.

The square root of 18128449 is about 4257.7516367210. The cubic root of 18128449 is about 262.6960542917.

The spelling of 18128449 in words is "eighteen million, one hundred twenty-eight thousand, four hundred forty-nine".