340391 has 4 divisors (see below), whose sum is σ = 360432. Its totient is φ = 320352.

The previous prime is 340387. The next prime is 340393. The reversal of 340391 is 193043.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 340391 - 2² = 340387 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 340391.

It is not an unprimeable number, because it can be changed into a prime (340393) 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, 9995 + ... + 10028.

It is an arithmetic number, because the mean of its divisors is an integer number (90108).

2³⁴⁰³⁹¹ is an apocalyptic number.

340391 is a deficient number, since it is larger than the sum of its proper divisors (20041).

340391 is a wasteful number, since it uses less digits than its factorization.

340391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20040.

The product of its (nonzero) digits is 324, while the sum is 20.

The square root of 340391 is about 583.4303728809. The cubic root of 340391 is about 69.8220650924.

The spelling of 340391 in words is "three hundred forty thousand, three hundred ninety-one".