666131 has 4 divisors (see below), whose sum is σ = 680352. Its totient is φ = 651912.

The previous prime is 666119. The next prime is 666139. The reversal of 666131 is 131666.

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 666131 - 2⁶ = 666067 is a prime.

It is a super-2 number, since 2×666131² = 887461018322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 666097 and 666106.

It is not an unprimeable number, because it can be changed into a prime (666139) 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, 7040 + ... + 7133.

It is an arithmetic number, because the mean of its divisors is an integer number (170088).

2⁶⁶⁶¹³¹ is an apocalyptic number.

666131 is a deficient number, since it is larger than the sum of its proper divisors (14221).

666131 is a wasteful number, since it uses less digits than its factorization.

666131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14220.

The product of its digits is 648, while the sum is 23.

The square root of 666131 is about 816.1684875073. The cubic root of 666131 is about 87.3346428074.

Adding to 666131 its reverse (131666), we get a palindrome (797797).

It can be divided in two parts, 666 and 131, that added together give a palindrome (797).

The spelling of 666131 in words is "six hundred sixty-six thousand, one hundred thirty-one".