18021530 has 32 divisors (see below), whose sum is σ = 34572096. Its totient is φ = 6740224.

The previous prime is 18021529. The next prime is 18021569. The reversal of 18021530 is 3512081.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 38357 + ... + 38823.

It is an arithmetic number, because the mean of its divisors is an integer number (1080378).

Almost surely, 2^18021530 is an apocalyptic number.

18021530 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18021530 is a deficient number, since it is larger than the sum of its proper divisors (16550566).

18021530 is a wasteful number, since it uses less digits than its factorization.

18021530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 718.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 18021530 is about 4245.1772636723. The cubic root of 18021530 is about 262.1785877181.

The spelling of 18021530 in words is "eighteen million, twenty-one thousand, five hundred thirty".