431209 has 4 divisors (see below), whose sum is σ = 438340. Its totient is φ = 424080.

The previous prime is 431203. The next prime is 431213. The reversal of 431209 is 902134.

431209 is nontrivially palindromic in base 8.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 67600 + 363609 = 260^2 + 603^2 .

It is a cyclic number.

It is not a de Polignac number, because 431209 - 2⁹ = 430697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (431203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3474 + ... + 3595.

It is an arithmetic number, because the mean of its divisors is an integer number (109585).

2⁴³¹²⁰⁹ is an apocalyptic number.

It is an amenable number.

431209 is a deficient number, since it is larger than the sum of its proper divisors (7131).

431209 is an equidigital number, since it uses as much as digits as its factorization.

431209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7130.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 431209 is about 656.6650592197. The cubic root of 431209 is about 75.5490960292.

It can be divided in two parts, 4 and 31209, that added together give a palindrome (31213).

The spelling of 431209 in words is "four hundred thirty-one thousand, two hundred nine".