131123205 has 30 divisors (see below), whose sum is σ = 235464306. Its totient is φ = 69809472.

The previous prime is 131123203. The next prime is 131123249. The reversal of 131123205 is 502321131.

It can be written as a sum of positive squares in 3 ways, for example, as 272484 + 130850721 = 522^2 + 11439^2 .

It is not a de Polignac number, because 131123205 - 2¹ = 131123203 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131123203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 230161 + ... + 230729.

Almost surely, 2^131123205 is an apocalyptic number.

131123205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

131123205 is a deficient number, since it is larger than the sum of its proper divisors (104341101).

131123205 is an frugal number, since it uses more digits than its factorization.

131123205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1155 (or 577 counting only the distinct ones).

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

The square root of 131123205 is about 11450.9041127764. The cubic root of 131123205 is about 508.0344761875.

Multiplying 131123205 by its product of nonzero digits (180), we get a square (23602176900 = 153630²).

Adding to 131123205 its reverse (502321131), we get a palindrome (633444336).

It can be divided in two parts, 131123 and 205, that added together give a triangular number (131328 = T₅₁₂).

The spelling of 131123205 in words is "one hundred thirty-one million, one hundred twenty-three thousand, two hundred five".