18228729 has 8 divisors (see below), whose sum is σ = 24328800. Its totient is φ = 12140576.

The previous prime is 18228703. The next prime is 18228797. The reversal of 18228729 is 92782281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18228729 - 2⁷ = 18228601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18228829) by changing a digit.

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, 1597 + ... + 6245.

It is an arithmetic number, because the mean of its divisors is an integer number (3041100).

Almost surely, 2^18228729 is an apocalyptic number.

It is an amenable number.

18228729 is a deficient number, since it is larger than the sum of its proper divisors (6100071).

18228729 is a wasteful number, since it uses less digits than its factorization.

18228729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5959.

The product of its digits is 32256, while the sum is 39.

The square root of 18228729 is about 4269.5115645704. The cubic root of 18228729 is about 263.1795436302.

The spelling of 18228729 in words is "eighteen million, two hundred twenty-eight thousand, seven hundred twenty-nine".