18841609 has 2 divisors, whose sum is σ = 18841610. Its totient is φ = 18841608.

The previous prime is 18841607. The next prime is 18841633. The reversal of 18841609 is 90614881.

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., 9859600 + 8982009 = 3140^2 + 2997^2 .

It is a cyclic number.

It is not a de Polignac number, because 18841609 - 2¹ = 18841607 is a prime.

Together with 18841607, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18841601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9420804 + 9420805.

It is an arithmetic number, because the mean of its divisors is an integer number (9420805).

Almost surely, 2^18841609 is an apocalyptic number.

It is an amenable number.

18841609 is a deficient number, since it is larger than the sum of its proper divisors (1).

18841609 is an equidigital number, since it uses as much as digits as its factorization.

18841609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 18841609 is about 4340.6922259013. The cubic root of 18841609 is about 266.0966021830.

The spelling of 18841609 in words is "eighteen million, eight hundred forty-one thousand, six hundred nine".