18386945 has 8 divisors (see below), whose sum is σ = 23362344. Its totient is φ = 13844224.

The previous prime is 18386923. The next prime is 18386947. The reversal of 18386945 is 54968381.

It is a Cunningham number, because it is equal to 4288²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 6615184 + 11771761 = 2572^2 + 3431^2 .

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 18386945 - 2⁶ = 18386881 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18386896 and 18386905.

It is not an unprimeable number, because it can be changed into a prime (18386947) 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, 108074 + ... + 108243.

It is an arithmetic number, because the mean of its divisors is an integer number (2920293).

Almost surely, 2^18386945 is an apocalyptic number.

It is an amenable number.

18386945 is a deficient number, since it is larger than the sum of its proper divisors (4975399).

18386945 is a wasteful number, since it uses less digits than its factorization.

18386945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216339.

The product of its digits is 207360, while the sum is 44.

The square root of 18386945 is about 4288.0001166045. Note that the first 3 decimals coincide. The cubic root of 18386945 is about 263.9387723406.

The spelling of 18386945 in words is "eighteen million, three hundred eighty-six thousand, nine hundred forty-five".