18728049906 has 16 divisors (see below), whose sum is σ = 41617888800. Its totient is φ = 6242683284.

The previous prime is 18728049829. The next prime is 18728049919. The reversal of 18728049906 is 60994082781.

18728049906 is a `hidden beast` number, since 1 + 8 + 72 + 80 + 499 + 0 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 346815739 = 18728049906 / (1 + 8 + 7 + 2 + 8 + 0 + 4 + 9 + 9 + 0 + 6).

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, 173407816 + ... + 173407923.

It is an arithmetic number, because the mean of its divisors is an integer number (2601118050).

Almost surely, 2^18728049906 is an apocalyptic number.

18728049906 is an abundant number, since it is smaller than the sum of its proper divisors (22889838894).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18728049906 is a wasteful number, since it uses less digits than its factorization.

18728049906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346815750 (or 346815744 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 54.

The spelling of 18728049906 in words is "eighteen billion, seven hundred twenty-eight million, forty-nine thousand, nine hundred six".