18009545 has 8 divisors (see below), whose sum is σ = 22882824. Its totient is φ = 13560064.

The previous prime is 18009539. The next prime is 18009547. The reversal of 18009545 is 54590081.

It can be written as a sum of positive squares in 4 ways, for example, as 2105401 + 15904144 = 1451^2 + 3988^2 .

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 18009545 - 2⁸ = 18009289 is a prime.

It is a super-2 number, since 2×18009545² = 648687422214050, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18009547) 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, 105854 + ... + 106023.

It is an arithmetic number, because the mean of its divisors is an integer number (2860353).

Almost surely, 2^18009545 is an apocalyptic number.

It is an amenable number.

18009545 is a deficient number, since it is larger than the sum of its proper divisors (4873279).

18009545 is a wasteful number, since it uses less digits than its factorization.

18009545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211899.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 18009545 is about 4243.7654270706. The cubic root of 18009545 is about 262.1204552659.

The spelling of 18009545 in words is "eighteen million, nine thousand, five hundred forty-five".