18382729 has 4 divisors (see below), whose sum is σ = 19464084. Its totient is φ = 17301376.

The previous prime is 18382669. The next prime is 18382733. The reversal of 18382729 is 92728381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 92728381 = 211 ⋅439471.

It can be written as a sum of positive squares in 2 ways, for example, as 15327225 + 3055504 = 3915^2 + 1748^2 .

It is not a de Polignac number, because 18382729 - 2⁷ = 18382601 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18382691 and 18382700.

It is not an unprimeable number, because it can be changed into a prime (18382759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is an upside-down number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 540652 + ... + 540685.

It is an arithmetic number, because the mean of its divisors is an integer number (4866021).

Almost surely, 2^18382729 is an apocalyptic number.

It is an amenable number.

18382729 is a deficient number, since it is larger than the sum of its proper divisors (1081355).

18382729 is a wasteful number, since it uses less digits than its factorization.

18382729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1081354.

The product of its digits is 48384, while the sum is 40.

The square root of 18382729 is about 4287.5084839566. The cubic root of 18382729 is about 263.9185976837.

The spelling of 18382729 in words is "eighteen million, three hundred eighty-two thousand, seven hundred twenty-nine".