340309 has 4 divisors (see below), whose sum is σ = 358240. Its totient is φ = 322380.

The previous prime is 340297. The next prime is 340321. The reversal of 340309 is 903043.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 903043 = 43 ⋅21001.

It is an interprime number because it is at equal distance from previous prime (340297) and next prime (340321).

It is a cyclic number.

It is not a de Polignac number, because 340309 - 2¹³ = 332117 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 17911 = 340309 / (3 + 4 + 0 + 3 + 0 + 9).

It is an Ulam number.

It is a Duffinian number.

340309 is a lucky number.

It is a nialpdrome in base 13.

It is a zygodrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (340339) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8937 + ... + 8974.

It is an arithmetic number, because the mean of its divisors is an integer number (89560).

2³⁴⁰³⁰⁹ is an apocalyptic number.

It is an amenable number.

340309 is a deficient number, since it is larger than the sum of its proper divisors (17931).

340309 is a wasteful number, since it uses less digits than its factorization.

340309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17930.

The product of its (nonzero) digits is 324, while the sum is 19.

The square root of 340309 is about 583.3600946242. The cubic root of 340309 is about 69.8164579435.

The spelling of 340309 in words is "three hundred forty thousand, three hundred nine".