340405 has 8 divisors (see below), whose sum is σ = 439992. Its totient is φ = 251328.

The previous prime is 340397. The next prime is 340409. The reversal of 340405 is 504043.

It can be written as a sum of positive squares in 4 ways, for example, as 34596 + 305809 = 186^2 + 553^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 340405 - 2³ = 340397 is a prime.

It is a super-3 number, since 3×340405³ = 118333864115790375, which contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (340409) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2554 + ... + 2683.

It is an arithmetic number, because the mean of its divisors is an integer number (54999).

2³⁴⁰⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

340405 is a deficient number, since it is larger than the sum of its proper divisors (99587).

340405 is a wasteful number, since it uses less digits than its factorization.

340405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5255.

The product of its (nonzero) digits is 240, while the sum is 16.

The square root of 340405 is about 583.4423707617. The cubic root of 340405 is about 69.8230223206.

Adding to 340405 its reverse (504043), we get a palindrome (844448).

The spelling of 340405 in words is "three hundred forty thousand, four hundred five".