18673729 has 2 divisors, whose sum is σ = 18673730. Its totient is φ = 18673728.

The previous prime is 18673703. The next prime is 18673763. The reversal of 18673729 is 92737681.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11122225 + 7551504 = 3335^2 + 2748^2 .

It is an emirp because it is prime and its reverse (92737681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18673729 - 2⁷ = 18673601 is a prime.

It is not a weakly prime, because it can be changed into another prime (18673229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9336864 + 9336865.

It is an arithmetic number, because the mean of its divisors is an integer number (9336865).

Almost surely, 2^18673729 is an apocalyptic number.

It is an amenable number.

18673729 is a deficient number, since it is larger than the sum of its proper divisors (1).

18673729 is an equidigital number, since it uses as much as digits as its factorization.

18673729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 127008, while the sum is 43.

The square root of 18673729 is about 4321.3110279173. The cubic root of 18673729 is about 265.3039303897.

The spelling of 18673729 in words is "eighteen million, six hundred seventy-three thousand, seven hundred twenty-nine".