18128813 has 2 divisors, whose sum is σ = 18128814. Its totient is φ = 18128812.

The previous prime is 18128801. The next prime is 18128821. The reversal of 18128813 is 31882181.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18088009 + 40804 = 4253^2 + 202^2 .

It is a cyclic number.

It is not a de Polignac number, because 18128813 - 2¹⁶ = 18063277 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18128813.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18128833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9064406 + 9064407.

It is an arithmetic number, because the mean of its divisors is an integer number (9064407).

Almost surely, 2^18128813 is an apocalyptic number.

It is an amenable number.

18128813 is a deficient number, since it is larger than the sum of its proper divisors (1).

18128813 is an equidigital number, since it uses as much as digits as its factorization.

18128813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3072, while the sum is 32.

The square root of 18128813 is about 4257.7943820715. The cubic root of 18128813 is about 262.6978124991.

The spelling of 18128813 in words is "eighteen million, one hundred twenty-eight thousand, eight hundred thirteen".