340 has 12 divisors (see below), whose sum is σ = 756. Its totient is φ = 128.

The previous prime is 337. The next prime is 347. The reversal of 340 is 43.

340 = T₁₁ + T₁₂ + ... + T₁₄.

340 is nontrivially palindromic in base 13.

It can be written as a sum of positive squares in 2 ways, for example, as 196 + 144 = 14^2 + 12^2 .

340 is an undulating number in base 13.

It is a plaindrome in base 11, base 12 and base 15.

It is a nialpdrome in base 4 and base 7.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (347) by changing a digit.

In principle, a polygon with 340 sides can be constructed with ruler and compass.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12 + ... + 28.

It is an arithmetic number, because the mean of its divisors is an integer number (63).

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (378).

340 is an abundant number, since it is smaller than the sum of its proper divisors (416).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

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

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

The sum of its prime factors is 26 (or 24 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 7.

The square root of 340 is about 18.4390889146. The cubic root of 340 is about 6.9795320469.

Adding to 340 its reverse (43), we get a palindrome (383).

It can be divided in two parts, 3 and 40, that multiplied together give a triangular number (120 = T₁₅).

The spelling of 340 in words is "three hundred forty", and thus it is an aban number and an iban number.