18028513 has 6 divisors (see below), whose sum is σ = 18255314. Its totient is φ = 17804496.

The previous prime is 18028499. The next prime is 18028519. The reversal of 18028513 is 31582081.

It can be written as a sum of positive squares in only one way, i.e., 17918289 + 110224 = 4233^2 + 332^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18028513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18028519) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5581 + ... + 8197.

Almost surely, 2^18028513 is an apocalyptic number.

It is an amenable number.

18028513 is a deficient number, since it is larger than the sum of its proper divisors (226801).

18028513 is an frugal number, since it uses more digits than its factorization.

18028513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2783 (or 2700 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 18028513 is about 4245.9996467263. Note that the first 3 decimals coincide. The cubic root of 18028513 is about 262.2124464168.

The spelling of 18028513 in words is "eighteen million, twenty-eight thousand, five hundred thirteen".