18386857 has 2 divisors, whose sum is σ = 18386858. Its totient is φ = 18386856.

The previous prime is 18386833. The next prime is 18386861. The reversal of 18386857 is 75868381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14470416 + 3916441 = 3804^2 + 1979^2 .

It is an emirp because it is prime and its reverse (75868381) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18386857 - 2²³ = 9998249 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18386807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9193428 + 9193429.

It is an arithmetic number, because the mean of its divisors is an integer number (9193429).

Almost surely, 2^18386857 is an apocalyptic number.

It is an amenable number.

18386857 is a deficient number, since it is larger than the sum of its proper divisors (1).

18386857 is an equidigital number, since it uses as much as digits as its factorization.

18386857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 322560, while the sum is 46.

The square root of 18386857 is about 4287.9898553984. The cubic root of 18386857 is about 263.9383512693.

The spelling of 18386857 in words is "eighteen million, three hundred eighty-six thousand, eight hundred fifty-seven".