66131 has 4 divisors (see below), whose sum is σ = 71232. Its totient is φ = 61032.

The previous prime is 66109. The next prime is 66137. The reversal of 66131 is 13166.

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

It is a cyclic number.

It is not a de Polignac number, because 66131 - 2⁶ = 66067 is a prime.

It is a super-2 number, since 2×66131² = 8746618322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66137) 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, 2531 + ... + 2556.

It is an arithmetic number, because the mean of its divisors is an integer number (17808).

2⁶⁶¹³¹ is an apocalyptic number.

66131 is a deficient number, since it is larger than the sum of its proper divisors (5101).

66131 is a wasteful number, since it uses less digits than its factorization.

66131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5100.

The product of its digits is 108, while the sum is 17.

The square root of 66131 is about 257.1594835895. The cubic root of 66131 is about 40.4391200328.

Adding to 66131 its reverse (13166), we get a palindrome (79297).

It can be divided in two parts, 66 and 131, that multiplied together give a triangular number (8646 = T₁₃₁).

The spelling of 66131 in words is "sixty-six thousand, one hundred thirty-one".