19609 has 2 divisors, whose sum is σ = 19610. Its totient is φ = 19608.

The previous prime is 19603. The next prime is 19661. The reversal of 19609 is 90691.

19609 is nontrivially palindromic in base 2.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19600 + 9 = 140^2 + 3^2 .

It is a cyclic number.

It is not a de Polignac number, because 19609 - 2⁵ = 19577 is a prime.

19609 is a lucky number.

It is a plaindrome in base 7.

It is a nialpdrome in base 12.

It is not a weakly prime, because it can be changed into another prime (19603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9804 + 9805.

It is an arithmetic number, because the mean of its divisors is an integer number (9805).

2¹⁹⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

19609 is a deficient number, since it is larger than the sum of its proper divisors (1).

19609 is an equidigital number, since it uses as much as digits as its factorization.

19609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 19609 is about 140.0321391681. The cubic root of 19609 is about 26.9661212022.

The spelling of 19609 in words is "nineteen thousand, six hundred nine".