18207857 has 2 divisors, whose sum is σ = 18207858. Its totient is φ = 18207856.

The previous prime is 18207809. The next prime is 18207859. The reversal of 18207857 is 75870281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15124321 + 3083536 = 3889^2 + 1756^2 .

It is a cyclic number.

It is not a de Polignac number, because 18207857 - 2¹⁸ = 17945713 is a prime.

Together with 18207859, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18207857.

It is not a weakly prime, because it can be changed into another prime (18207859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9103928 + 9103929.

It is an arithmetic number, because the mean of its divisors is an integer number (9103929).

Almost surely, 2^18207857 is an apocalyptic number.

It is an amenable number.

18207857 is a deficient number, since it is larger than the sum of its proper divisors (1).

18207857 is an equidigital number, since it uses as much as digits as its factorization.

18207857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31360, while the sum is 38.

The square root of 18207857 is about 4267.0665567811. The cubic root of 18207857 is about 263.0790579023.

The spelling of 18207857 in words is "eighteen million, two hundred seven thousand, eight hundred fifty-seven".