131569 has 4 divisors (see below), whose sum is σ = 134820. Its totient is φ = 128320.

The previous prime is 131561. The next prime is 131581. The reversal of 131569 is 965131.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 34225 + 97344 = 185^2 + 312^2 .

It is a cyclic number.

It is not a de Polignac number, because 131569 - 2³ = 131561 is a prime.

It is a super-2 number, since 2×131569² = 34620803522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131561) 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, 1564 + ... + 1645.

It is an arithmetic number, because the mean of its divisors is an integer number (33705).

2¹³¹⁵⁶⁹ is an apocalyptic number.

It is an amenable number.

131569 is a deficient number, since it is larger than the sum of its proper divisors (3251).

131569 is an equidigital number, since it uses as much as digits as its factorization.

131569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3250.

The product of its digits is 810, while the sum is 25.

The square root of 131569 is about 362.7244132947. The cubic root of 131569 is about 50.8609566488.

The spelling of 131569 in words is "one hundred thirty-one thousand, five hundred sixty-nine".