131557 has 4 divisors (see below), whose sum is σ = 132300. Its totient is φ = 130816.

The previous prime is 131543. The next prime is 131561. The reversal of 131557 is 755131.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 106276 + 25281 = 326^2 + 159^2 .

It is a cyclic number.

It is not a de Polignac number, because 131557 - 2¹¹ = 129509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69 + ... + 517.

It is an arithmetic number, because the mean of its divisors is an integer number (33075).

2¹³¹⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

131557 is a deficient number, since it is larger than the sum of its proper divisors (743).

131557 is an equidigital number, since it uses as much as digits as its factorization.

131557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 742.

The product of its digits is 525, while the sum is 22.

The square root of 131557 is about 362.7078714337. The cubic root of 131557 is about 50.8594103119.

Adding to 131557 its reverse (755131), we get a palindrome (886688).

The spelling of 131557 in words is "one hundred thirty-one thousand, five hundred fifty-seven".