18918307 has 2 divisors, whose sum is σ = 18918308. Its totient is φ = 18918306.

The previous prime is 18918253. The next prime is 18918313. The reversal of 18918307 is 70381981.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18918307 is a prime.

It is not a weakly prime, because it can be changed into another prime (18916307) 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, 9459153 + 9459154.

It is an arithmetic number, because the mean of its divisors is an integer number (9459154).

Almost surely, 2^18918307 is an apocalyptic number.

18918307 is a deficient number, since it is larger than the sum of its proper divisors (1).

18918307 is an equidigital number, since it uses as much as digits as its factorization.

18918307 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 18918307 is about 4349.5180192752. The cubic root of 18918307 is about 266.4571773117.

It can be divided in two parts, 189 and 18307, that added together give a square (18496 = 136²).

The spelling of 18918307 in words is "eighteen million, nine hundred eighteen thousand, three hundred seven".