131869 has 4 divisors (see below), whose sum is σ = 139644. Its totient is φ = 124096.

The previous prime is 131861. The next prime is 131891. The reversal of 131869 is 968131.

131869 = T₂₉₅ + T₂₉₆ + T₂₉₇.

131869 = 45² + 46² + ... + 78².

It is a happy number.

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 105625 + 26244 = 325^2 + 162^2 .

It is a cyclic number.

It is not a de Polignac number, because 131869 - 2³ = 131861 is a prime.

It is a super-2 number, since 2×131869² = 34778866322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131861) 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, 3862 + ... + 3895.

It is an arithmetic number, because the mean of its divisors is an integer number (34911).

2¹³¹⁸⁶⁹ is an apocalyptic number.

131869 is the 297-th centered triangular number.

It is an amenable number.

131869 is a deficient number, since it is larger than the sum of its proper divisors (7775).

131869 is an equidigital number, since it uses as much as digits as its factorization.

131869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7774.

The product of its digits is 1296, while the sum is 28.

The square root of 131869 is about 363.1377149237. The cubic root of 131869 is about 50.8995845538.

Subtracting from 131869 its sum of digits (28), we obtain a triangular number (131841 = T₅₁₃).

It can be divided in two parts, 131 and 869, that added together give a cube (1000 = 10³).

The spelling of 131869 in words is "one hundred thirty-one thousand, eight hundred sixty-nine".