18947311 has 2 divisors, whose sum is σ = 18947312. Its totient is φ = 18947310.

The previous prime is 18947213. The next prime is 18947321. The reversal of 18947311 is 11374981.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18947311 - 2⁷ = 18947183 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18947321) 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, 9473655 + 9473656.

It is an arithmetic number, because the mean of its divisors is an integer number (9473656).

Almost surely, 2^18947311 is an apocalyptic number.

18947311 is a deficient number, since it is larger than the sum of its proper divisors (1).

18947311 is an equidigital number, since it uses as much as digits as its factorization.

18947311 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 34.

The square root of 18947311 is about 4352.8509048668. The cubic root of 18947311 is about 266.5932778950.

The spelling of 18947311 in words is "eighteen million, nine hundred forty-seven thousand, three hundred eleven".