18130561 has 8 divisors (see below), whose sum is σ = 18402440. Its totient is φ = 17860608.

The previous prime is 18130559. The next prime is 18130583. The reversal of 18130561 is 16503181.

It can be written as a sum of positive squares in 4 ways, for example, as 9610000 + 8520561 = 3100^2 + 2919^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18130561 - 2¹ = 18130559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18130591) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39445 + ... + 39901.

It is an arithmetic number, because the mean of its divisors is an integer number (2300305).

Almost surely, 2^18130561 is an apocalyptic number.

It is an amenable number.

18130561 is a deficient number, since it is larger than the sum of its proper divisors (271879).

18130561 is an equidigital number, since it uses as much as digits as its factorization.

18130561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 963.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 18130561 is about 4257.9996477219. Note that the first 3 decimals coincide. The cubic root of 18130561 is about 262.7062554314.

The spelling of 18130561 in words is "eighteen million, one hundred thirty thousand, five hundred sixty-one".