18380545 has 4 divisors (see below), whose sum is σ = 22056660. Its totient is φ = 14704432.

The previous prime is 18380539. The next prime is 18380563. The reversal of 18380545 is 54508381.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7311616 + 11068929 = 2704^2 + 3327^2 .

It is a cyclic number.

It is not a de Polignac number, because 18380545 - 2¹¹ = 18378497 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18380545.

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, 1838050 + ... + 1838059.

It is an arithmetic number, because the mean of its divisors is an integer number (5514165).

Almost surely, 2^18380545 is an apocalyptic number.

It is an amenable number.

18380545 is a deficient number, since it is larger than the sum of its proper divisors (3676115).

18380545 is an equidigital number, since it uses as much as digits as its factorization.

18380545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3676114.

The product of its (nonzero) digits is 19200, while the sum is 34.

The square root of 18380545 is about 4287.2537830177. The cubic root of 18380545 is about 263.9081454625.

It can be divided in two parts, 183 and 80545, that multiplied together give a triangular number (14739735 = T₅₄₂₉).

The spelling of 18380545 in words is "eighteen million, three hundred eighty thousand, five hundred forty-five".