203409 has 12 divisors (see below), whose sum is σ = 298116. Its totient is φ = 133632.

The previous prime is 203393. The next prime is 203417. The reversal of 203409 is 904302.

It can be written as a sum of positive squares in 2 ways, for example, as 65025 + 138384 = 255^2 + 372^2 .

It is not a de Polignac number, because 203409 - 2⁴ = 203393 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 203391 and 203400.

It is not an unprimeable number, because it can be changed into a prime (203419) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 757 + ... + 989.

It is an arithmetic number, because the mean of its divisors is an integer number (24843).

2²⁰³⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

203409 is a deficient number, since it is larger than the sum of its proper divisors (94707).

203409 is a wasteful number, since it uses less digits than its factorization.

203409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336 (or 333 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 203409 is about 451.0088690924. The cubic root of 203409 is about 58.8107504986.

The spelling of 203409 in words is "two hundred three thousand, four hundred nine".