18628729 has 8 divisors (see below), whose sum is σ = 21639488. Its totient is φ = 15705360.

The previous prime is 18628717. The next prime is 18628733. The reversal of 18628729 is 92782681.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18628729 - 2⁵ = 18628697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18628429) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21387 + ... + 22240.

It is an arithmetic number, because the mean of its divisors is an integer number (2704936).

Almost surely, 2^18628729 is an apocalyptic number.

It is an amenable number.

18628729 is a deficient number, since it is larger than the sum of its proper divisors (3010759).

18628729 is an equidigital number, since it uses as much as digits as its factorization.

18628729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43695.

The product of its digits is 96768, while the sum is 43.

The square root of 18628729 is about 4316.1011341256. The cubic root of 18628729 is about 265.0906489453.

The spelling of 18628729 in words is "eighteen million, six hundred twenty-eight thousand, seven hundred twenty-nine".