18206945 has 4 divisors (see below), whose sum is σ = 21848340. Its totient is φ = 14565552.

The previous prime is 18206939. The next prime is 18206953. The reversal of 18206945 is 54960281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54960281 = 37 ⋅1485413.

It can be written as a sum of positive squares in 2 ways, for example, as 10764961 + 7441984 = 3281^2 + 2728^2 .

It is a cyclic number.

It is not a de Polignac number, because 18206945 - 2⁸ = 18206689 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1820690 + ... + 1820699.

It is an arithmetic number, because the mean of its divisors is an integer number (5462085).

Almost surely, 2^18206945 is an apocalyptic number.

It is an amenable number.

18206945 is a deficient number, since it is larger than the sum of its proper divisors (3641395).

18206945 is an equidigital number, since it uses as much as digits as its factorization.

18206945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3641394.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 18206945 is about 4266.9596904588. The cubic root of 18206945 is about 263.0746654376.

The spelling of 18206945 in words is "eighteen million, two hundred six thousand, nine hundred forty-five".