18001729 has 2 divisors, whose sum is σ = 18001730. Its totient is φ = 18001728.

The previous prime is 18001723. The next prime is 18001811. The reversal of 18001729 is 92710081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14288400 + 3713329 = 3780^2 + 1927^2 .

It is a cyclic number.

It is not a de Polignac number, because 18001729 - 2⁷ = 18001601 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18001697 and 18001706.

It is not a weakly prime, because it can be changed into another prime (18001723) 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 as a sum of consecutive naturals, namely, 9000864 + 9000865.

It is an arithmetic number, because the mean of its divisors is an integer number (9000865).

Almost surely, 2^18001729 is an apocalyptic number.

It is an amenable number.

18001729 is a deficient number, since it is larger than the sum of its proper divisors (1).

18001729 is an equidigital number, since it uses as much as digits as its factorization.

18001729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 18001729 is about 4242.8444468305. The cubic root of 18001729 is about 262.0825303779.

The spelling of 18001729 in words is "eighteen million, one thousand, seven hundred twenty-nine".