19309 has 2 divisors, whose sum is σ = 19310. Its totient is φ = 19308.

The previous prime is 19301. The next prime is 19319. The reversal of 19309 is 90391.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13225 + 6084 = 115^2 + 78^2 .

It is a cyclic number.

It is not a de Polignac number, because 19309 - 2³ = 19301 is a prime.

It is an Ulam number.

19309 is a lucky number.

It is a plaindrome in base 8.

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 19309.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9654 + 9655.

It is an arithmetic number, because the mean of its divisors is an integer number (9655).

2¹⁹³⁰⁹ is an apocalyptic number.

It is an amenable number.

19309 is a deficient number, since it is larger than the sum of its proper divisors (1).

19309 is an equidigital number, since it uses as much as digits as its factorization.

19309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 243, while the sum is 22.

The square root of 19309 is about 138.9568278279. The cubic root of 19309 is about 26.8278947694.

The spelling of 19309 in words is "nineteen thousand, three hundred nine".