18028515 has 32 divisors (see below), whose sum is σ = 30099456. Its totient is φ = 9204480.

The previous prime is 18028499. The next prime is 18028519. The reversal of 18028515 is 51582081.

It is a Cunningham number, because it is equal to 4246²-1.

It is not a de Polignac number, because 18028515 - 2⁴ = 18028499 is a prime.

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

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 63564 + ... + 63846.

It is an arithmetic number, because the mean of its divisors is an integer number (940608).

Almost surely, 2^18028515 is an apocalyptic number.

18028515 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

18028515 is a deficient number, since it is larger than the sum of its proper divisors (12070941).

18028515 is a wasteful number, since it uses less digits than its factorization.

18028515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459.

The product of its (nonzero) digits is 3200, while the sum is 30.

The square root of 18028515 is about 4245.9998822421. Note that the first 3 decimals coincide. The cubic root of 18028515 is about 262.2124561130.

It can be divided in two parts, 180285 and 15, that added together give a triangular number (180300 = T₆₀₀).

The spelling of 18028515 in words is "eighteen million, twenty-eight thousand, five hundred fifteen".