18227945 has 4 divisors (see below), whose sum is σ = 21873540. Its totient is φ = 14582352.

The previous prime is 18227941. The next prime is 18227947. The reversal of 18227945 is 54972281.

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 7678441 + 10549504 = 2771^2 + 3248^2 .

It is a cyclic number.

It is not a de Polignac number, because 18227945 - 2² = 18227941 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18227899 and 18227908.

It is not an unprimeable number, because it can be changed into a prime (18227941) by changing a digit.

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, 1822790 + ... + 1822799.

It is an arithmetic number, because the mean of its divisors is an integer number (5468385).

Almost surely, 2^18227945 is an apocalyptic number.

It is an amenable number.

18227945 is a deficient number, since it is larger than the sum of its proper divisors (3645595).

18227945 is an equidigital number, since it uses as much as digits as its factorization.

18227945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3645594.

The product of its digits is 40320, while the sum is 38.

The square root of 18227945 is about 4269.4197498021. The cubic root of 18227945 is about 263.1757705436.

The spelling of 18227945 in words is "eighteen million, two hundred twenty-seven thousand, nine hundred forty-five".