18814909 has 2 divisors, whose sum is σ = 18814910. Its totient is φ = 18814908.

The previous prime is 18814891. The next prime is 18814967. The reversal of 18814909 is 90941881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9796900 + 9018009 = 3130^2 + 3003^2 .

It is an emirp because it is prime and its reverse (90941881) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18814909 - 2⁷ = 18814781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18814979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9407454 + 9407455.

It is an arithmetic number, because the mean of its divisors is an integer number (9407455).

Almost surely, 2^18814909 is an apocalyptic number.

It is an amenable number.

18814909 is a deficient number, since it is larger than the sum of its proper divisors (1).

18814909 is an equidigital number, since it uses as much as digits as its factorization.

18814909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 18814909 is about 4337.6155892379. The cubic root of 18814909 is about 265.9708496897.

The spelling of 18814909 in words is "eighteen million, eight hundred fourteen thousand, nine hundred nine".