131866 has 8 divisors (see below), whose sum is σ = 226080. Its totient is φ = 56508.

The previous prime is 131861. The next prime is 131891. The reversal of 131866 is 668131.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 131866.

It is not an unprimeable number, because it can be changed into a prime (131861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4696 + ... + 4723.

It is an arithmetic number, because the mean of its divisors is an integer number (28260).

2¹³¹⁸⁶⁶ is an apocalyptic number.

131866 is a deficient number, since it is larger than the sum of its proper divisors (94214).

131866 is an equidigital number, since it uses as much as digits as its factorization.

131866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9428.

The product of its digits is 864, while the sum is 25.

The square root of 131866 is about 363.1335842359. The cubic root of 131866 is about 50.8991985649.

Subtracting from 131866 its sum of digits (25), we obtain a triangular number (131841 = T₅₁₃).

Adding to 131866 its reverse (668131), we get a palindrome (799997).

The spelling of 131866 in words is "one hundred thirty-one thousand, eight hundred sixty-six".