18188545 has 4 divisors (see below), whose sum is σ = 21826260. Its totient is φ = 14550832.

The previous prime is 18188477. The next prime is 18188563. The reversal of 18188545 is 54588181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54588181 = 109 ⋅500809.

It can be written as a sum of positive squares in 2 ways, for example, as 7059649 + 11128896 = 2657^2 + 3336^2 .

It is a cyclic number.

It is not a de Polignac number, because 18188545 - 2⁹ = 18188033 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 18188498 and 18188507.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1818850 + ... + 1818859.

It is an arithmetic number, because the mean of its divisors is an integer number (5456565).

Almost surely, 2^18188545 is an apocalyptic number.

It is an amenable number.

18188545 is a deficient number, since it is larger than the sum of its proper divisors (3637715).

18188545 is an equidigital number, since it uses as much as digits as its factorization.

18188545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3637714.

The product of its digits is 51200, while the sum is 40.

The square root of 18188545 is about 4264.8030435180. The cubic root of 18188545 is about 262.9860141859.

The spelling of 18188545 in words is "eighteen million, one hundred eighty-eight thousand, five hundred forty-five".