18317947 has 2 divisors, whose sum is σ = 18317948. Its totient is φ = 18317946.

The previous prime is 18317941. The next prime is 18317951. The reversal of 18317947 is 74971381.

It is a strong prime.

It is an emirp because it is prime and its reverse (74971381) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18317947 is a prime.

It is not a weakly prime, because it can be changed into another prime (18317941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9158973 + 9158974.

It is an arithmetic number, because the mean of its divisors is an integer number (9158974).

Almost surely, 2^18317947 is an apocalyptic number.

18317947 is a deficient number, since it is larger than the sum of its proper divisors (1).

18317947 is an equidigital number, since it uses as much as digits as its factorization.

18317947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42336, while the sum is 40.

The square root of 18317947 is about 4279.9470791121. The cubic root of 18317947 is about 263.6082103652.

The spelling of 18317947 in words is "eighteen million, three hundred seventeen thousand, nine hundred forty-seven".