131731405 has 16 divisors (see below), whose sum is σ = 171808560. Its totient is φ = 96380928.

The previous prime is 131731399. The next prime is 131731417. The reversal of 131731405 is 504137131.

It can be written as a sum of positive squares in 8 ways, for example, as 2022084 + 129709321 = 1422^2 + 11389^2 .

It is a cyclic number.

It is not a de Polignac number, because 131731405 - 2⁷ = 131731277 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 131731405.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2212 + ... + 16381.

It is an arithmetic number, because the mean of its divisors is an integer number (10738035).

Almost surely, 2^131731405 is an apocalyptic number.

It is an amenable number.

131731405 is a deficient number, since it is larger than the sum of its proper divisors (40077155).

131731405 is a wasteful number, since it uses less digits than its factorization.

131731405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18720.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 131731405 is about 11477.4302437436. The cubic root of 131731405 is about 508.8187514618.

Adding to 131731405 its reverse (504137131), we get a palindrome (635868536).

The spelling of 131731405 in words is "one hundred thirty-one million, seven hundred thirty-one thousand, four hundred five".