18228809 has 16 divisors (see below), whose sum is σ = 19872000. Its totient is φ = 16665984.

The previous prime is 18228797. The next prime is 18228829. The reversal of 18228809 is 90882281.

It is a cyclic number.

It is not a de Polignac number, because 18228809 - 2¹⁶ = 18163273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18228829) 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, 122267 + ... + 122415.

It is an arithmetic number, because the mean of its divisors is an integer number (1242000).

Almost surely, 2^18228809 is an apocalyptic number.

18228809 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

18228809 is a deficient number, since it is larger than the sum of its proper divisors (1643191).

18228809 is a wasteful number, since it uses less digits than its factorization.

18228809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352.

The product of its (nonzero) digits is 18432, while the sum is 38.

The square root of 18228809 is about 4269.5209333132. The cubic root of 18228809 is about 263.1799286330.

The spelling of 18228809 in words is "eighteen million, two hundred twenty-eight thousand, eight hundred nine".