209231 has 8 divisors (see below), whose sum is σ = 238464. Its totient is φ = 181720.

The previous prime is 209227. The next prime is 209233. The reversal of 209231 is 132902.

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

It is not a de Polignac number, because 209231 - 2² = 209227 is a prime.

It is a super-2 number, since 2×209231² = 87555222722, which contains 22 as substring.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 209231.

It is not an unprimeable number, because it can be changed into a prime (209233) 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, 161 + ... + 666.

It is an arithmetic number, because the mean of its divisors is an integer number (29808).

2²⁰⁹²³¹ is an apocalyptic number.

209231 is the 245-th centered heptagonal number.

209231 is a deficient number, since it is larger than the sum of its proper divisors (29233).

209231 is a wasteful number, since it uses less digits than its factorization.

209231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 861.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 209231 is about 457.4177521697. The cubic root of 209231 is about 59.3665771986.

The spelling of 209231 in words is "two hundred nine thousand, two hundred thirty-one".