18516947 has 2 divisors, whose sum is σ = 18516948. Its totient is φ = 18516946.

The previous prime is 18516937. The next prime is 18516989. The reversal of 18516947 is 74961581.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18516947 - 2²² = 14322643 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18516907) 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, 9258473 + 9258474.

It is an arithmetic number, because the mean of its divisors is an integer number (9258474).

Almost surely, 2^18516947 is an apocalyptic number.

18516947 is a deficient number, since it is larger than the sum of its proper divisors (1).

18516947 is an equidigital number, since it uses as much as digits as its factorization.

18516947 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 18516947 is about 4303.1322312939. The cubic root of 18516947 is about 264.5593578925.

The spelling of 18516947 in words is "eighteen million, five hundred sixteen thousand, nine hundred forty-seven".