133666 has 16 divisors (see below), whose sum is σ = 222264. Its totient is φ = 59904.

The previous prime is 133657. The next prime is 133669. The reversal of 133666 is 666331.

It can be written as a sum of positive squares in 4 ways, for example, as 103041 + 30625 = 321^2 + 175^2 .

It is a plaindrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 133666.

It is not an unprimeable number, because it can be changed into a prime (133669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1330 + ... + 1426.

2¹³³⁶⁶⁶ is an apocalyptic number.

133666 is a deficient number, since it is larger than the sum of its proper divisors (88598).

133666 is a wasteful number, since it uses less digits than its factorization.

133666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165.

The product of its digits is 1944, while the sum is 25.

The square root of 133666 is about 365.6036104855. The cubic root of 133666 is about 51.1297478070.

Adding to 133666 its reverse (666331), we get a palindrome (799997).

The spelling of 133666 in words is "one hundred thirty-three thousand, six hundred sixty-six".