18471728 has 20 divisors (see below), whose sum is σ = 39042888. Its totient is φ = 8396160.

The previous prime is 18471727. The next prime is 18471749. The reversal of 18471728 is 82717481.

It is a junction number, because it is equal to n+sod(n) for n = 18471691 and 18471700.

It is not an unprimeable number, because it can be changed into a prime (18471727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52301 + ... + 52652.

Almost surely, 2^18471728 is an apocalyptic number.

It is an amenable number.

18471728 is an abundant number, since it is smaller than the sum of its proper divisors (20571160).

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

18471728 is a wasteful number, since it uses less digits than its factorization.

18471728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104972 (or 104966 counting only the distinct ones).

The product of its digits is 25088, while the sum is 38.

The square root of 18471728 is about 4297.8748236774. The cubic root of 18471728 is about 264.3438281053.

The spelling of 18471728 in words is "eighteen million, four hundred seventy-one thousand, seven hundred twenty-eight".