205131231 has 16 divisors (see below), whose sum is σ = 321775200. Its totient is φ = 128709504.

The previous prime is 205131229. The next prime is 205131307. The reversal of 205131231 is 132131502.

It is not a de Polignac number, because 205131231 - 2¹ = 205131229 is a prime.

It is a super-2 number, since 2×205131231² = 84157643863150722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205131211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 222996 + ... + 223913.

It is an arithmetic number, because the mean of its divisors is an integer number (20110950).

Almost surely, 2^205131231 is an apocalyptic number.

205131231 is a deficient number, since it is larger than the sum of its proper divisors (116643969).

205131231 is a wasteful number, since it uses less digits than its factorization.

205131231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 446935 (or 446929 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 205131231 is about 14322.4031153993. The cubic root of 205131231 is about 589.7626460759.

Adding to 205131231 its reverse (132131502), we get a palindrome (337262733).

The spelling of 205131231 in words is "two hundred five million, one hundred thirty-one thousand, two hundred thirty-one".