345409 has 4 divisors (see below), whose sum is σ = 349380. Its totient is φ = 341440.

The previous prime is 345379. The next prime is 345413. The reversal of 345409 is 904543.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 904543 = 73 ⋅12391.

It can be written as a sum of positive squares in 2 ways, for example, as 138384 + 207025 = 372^2 + 455^2 .

It is a cyclic number.

It is not a de Polignac number, because 345409 - 2¹³ = 337217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (345479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1852 + ... + 2029.

It is an arithmetic number, because the mean of its divisors is an integer number (87345).

2³⁴⁵⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

345409 is a deficient number, since it is larger than the sum of its proper divisors (3971).

345409 is an equidigital number, since it uses as much as digits as its factorization.

345409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3970.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 345409 is about 587.7150670180. The cubic root of 345409 is about 70.1634953860.

The spelling of 345409 in words is "three hundred forty-five thousand, four hundred nine".