18423729 has 12 divisors (see below), whose sum is σ = 27530100. Its totient is φ = 11858784.

The previous prime is 18423679. The next prime is 18423751. The reversal of 18423729 is 92732481.

It can be written as a sum of positive squares in 2 ways, for example, as 7033104 + 11390625 = 2652^2 + 3375^2 .

It is not a de Polignac number, because 18423729 - 2¹¹ = 18421681 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18423693 and 18423702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18423799) 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 11 ways as a sum of consecutive naturals, for example, 35034 + ... + 35555.

It is an arithmetic number, because the mean of its divisors is an integer number (2294175).

Almost surely, 2^18423729 is an apocalyptic number.

It is an amenable number.

18423729 is a deficient number, since it is larger than the sum of its proper divisors (9106371).

18423729 is a wasteful number, since it uses less digits than its factorization.

18423729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70624 (or 70621 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 18423729 is about 4292.2871525563. The cubic root of 18423729 is about 264.1146626571.

The spelling of 18423729 in words is "eighteen million, four hundred twenty-three thousand, seven hundred twenty-nine".