18128879 has 2 divisors, whose sum is σ = 18128880. Its totient is φ = 18128878.

The previous prime is 18128863. The next prime is 18128897. The reversal of 18128879 is 97882181.

Together with next prime (18128897) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18128879 - 2⁴ = 18128863 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18128839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9064439 + 9064440.

It is an arithmetic number, because the mean of its divisors is an integer number (9064440).

Almost surely, 2^18128879 is an apocalyptic number.

18128879 is a deficient number, since it is larger than the sum of its proper divisors (1).

18128879 is an equidigital number, since it uses as much as digits as its factorization.

18128879 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64512, while the sum is 44.

The square root of 18128879 is about 4257.8021325562. The cubic root of 18128879 is about 262.6981312925.

The spelling of 18128879 in words is "eighteen million, one hundred twenty-eight thousand, eight hundred seventy-nine".