18131729 has 12 divisors (see below), whose sum is σ = 22778112. Its totient is φ = 14127960.

The previous prime is 18131713. The next prime is 18131731. The reversal of 18131729 is 92713181.

It is not a de Polignac number, because 18131729 - 2⁴ = 18131713 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18131695 and 18131704.

It is not an unprimeable number, because it can be changed into a prime (18131759) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9857 + ... + 11550.

It is an arithmetic number, because the mean of its divisors is an integer number (1898176).

Almost surely, 2^18131729 is an apocalyptic number.

It is an amenable number.

18131729 is a deficient number, since it is larger than the sum of its proper divisors (4646383).

18131729 is a wasteful number, since it uses less digits than its factorization.

18131729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21436 (or 21425 counting only the distinct ones).

The product of its digits is 3024, while the sum is 32.

The square root of 18131729 is about 4258.1367991177. The cubic root of 18131729 is about 262.7118966305.

It can be divided in two parts, 1813172 and 9, that added together give a palindrome (1813181).

The spelling of 18131729 in words is "eighteen million, one hundred thirty-one thousand, seven hundred twenty-nine".