18865709 has 2 divisors, whose sum is σ = 18865710. Its totient is φ = 18865708.

The previous prime is 18865697. The next prime is 18865729. The reversal of 18865709 is 90756881.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11710084 + 7155625 = 3422^2 + 2675^2 .

It is an emirp because it is prime and its reverse (90756881) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18865709 - 2²⁰ = 17817133 is a prime.

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 18865709.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18865729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9432854 + 9432855.

It is an arithmetic number, because the mean of its divisors is an integer number (9432855).

Almost surely, 2^18865709 is an apocalyptic number.

It is an amenable number.

18865709 is a deficient number, since it is larger than the sum of its proper divisors (1).

18865709 is an equidigital number, since it uses as much as digits as its factorization.

18865709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 44.

The square root of 18865709 is about 4343.4673936845. The cubic root of 18865709 is about 266.2100071445.

The spelling of 18865709 in words is "eighteen million, eight hundred sixty-five thousand, seven hundred nine".