18430729 has 4 divisors (see below), whose sum is σ = 18524484. Its totient is φ = 18336976.

The previous prime is 18430691. The next prime is 18430733. The reversal of 18430729 is 92703481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 92703481 = 13 ⋅7131037.

It can be written as a sum of positive squares in 2 ways, for example, as 12766329 + 5664400 = 3573^2 + 2380^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18430729 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18430694 and 18430703.

It is not an unprimeable number, because it can be changed into a prime (18430739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46582 + ... + 46975.

It is an arithmetic number, because the mean of its divisors is an integer number (4631121).

Almost surely, 2^18430729 is an apocalyptic number.

It is an amenable number.

18430729 is a deficient number, since it is larger than the sum of its proper divisors (93755).

18430729 is an equidigital number, since it uses as much as digits as its factorization.

18430729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93754.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 18430729 is about 4293.1024912061. The cubic root of 18430729 is about 264.1481080858.

The spelling of 18430729 in words is "eighteen million, four hundred thirty thousand, seven hundred twenty-nine".