18206728 has 16 divisors (see below), whose sum is σ = 36145980. Its totient is φ = 8567808.

The previous prime is 18206723. The next prime is 18206729. The reversal of 18206728 is 82760281.

It can be written as a sum of positive squares in 2 ways, for example, as 17288964 + 917764 = 4158^2 + 958^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 18206693 and 18206702.

It is not an unprimeable number, because it can be changed into a prime (18206723) 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, 66801 + ... + 67072.

Almost surely, 2^18206728 is an apocalyptic number.

It is an amenable number.

18206728 is a deficient number, since it is larger than the sum of its proper divisors (17939252).

18206728 is a wasteful number, since it uses less digits than its factorization.

18206728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133896 (or 133892 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 18206728 is about 4266.9342624418. The cubic root of 18206728 is about 263.0736202791.

The spelling of 18206728 in words is "eighteen million, two hundred six thousand, seven hundred twenty-eight".