18156947 has 2 divisors, whose sum is σ = 18156948. Its totient is φ = 18156946.

The previous prime is 18156923. The next prime is 18156949. The reversal of 18156947 is 74965181.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18156947 - 2¹⁰ = 18155923 is a prime.

Together with 18156949, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18156949) 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 as a sum of consecutive naturals, namely, 9078473 + 9078474.

It is an arithmetic number, because the mean of its divisors is an integer number (9078474).

Almost surely, 2^18156947 is an apocalyptic number.

18156947 is a deficient number, since it is larger than the sum of its proper divisors (1).

18156947 is an equidigital number, since it uses as much as digits as its factorization.

18156947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 41.

The square root of 18156947 is about 4261.0969245020. The cubic root of 18156947 is about 262.8336353342.

The spelling of 18156947 in words is "eighteen million, one hundred fifty-six thousand, nine hundred forty-seven".