18728049905 has 8 divisors (see below), whose sum is σ = 23021798184. Its totient is φ = 14617014400.

The previous prime is 18728049829. The next prime is 18728049919. The reversal of 18728049905 is 50994082781.

It can be written as a sum of positive squares in 4 ways, for example, as 26666896 + 18701383009 = 5164^2 + 136753^2 .

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

It is not a de Polignac number, because 18728049905 - 2⁸ = 18728049649 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45677966 + ... + 45678375.

It is an arithmetic number, because the mean of its divisors is an integer number (2877724773).

Almost surely, 2^18728049905 is an apocalyptic number.

It is an amenable number.

18728049905 is a deficient number, since it is larger than the sum of its proper divisors (4293748279).

18728049905 is an equidigital number, since it uses as much as digits as its factorization.

18728049905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91356387.

The product of its (nonzero) digits is 1451520, while the sum is 53.

The spelling of 18728049905 in words is "eighteen billion, seven hundred twenty-eight million, forty-nine thousand, nine hundred five".