340639 has 4 divisors (see below), whose sum is σ = 366856. Its totient is φ = 314424.

The previous prime is 340633. The next prime is 340643. The reversal of 340639 is 936043.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 936043 = 307 ⋅3049.

It is a cyclic number.

It is not a de Polignac number, because 340639 - 2⁹ = 340127 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (340633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13089 + ... + 13114.

It is an arithmetic number, because the mean of its divisors is an integer number (91714).

2³⁴⁰⁶³⁹ is an apocalyptic number.

340639 is a deficient number, since it is larger than the sum of its proper divisors (26217).

340639 is a wasteful number, since it uses less digits than its factorization.

340639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26216.

The product of its (nonzero) digits is 1944, while the sum is 25.

The square root of 340639 is about 583.6428702554. The cubic root of 340639 is about 69.8390178209.

It can be divided in two parts, 340 and 639, that added together give a palindrome (979).

The spelling of 340639 in words is "three hundred forty thousand, six hundred thirty-nine".