133605666 has 64 divisors (see below), whose sum is σ = 313286400. Its totient is φ = 42121728.

The previous prime is 133605653. The next prime is 133605671. The reversal of 133605666 is 666506331.

It is a happy number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 133605666.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 119920 + ... + 121028.

It is an arithmetic number, because the mean of its divisors is an integer number (4895100).

Almost surely, 2^133605666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 133605666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156643200).

133605666 is an abundant number, since it is smaller than the sum of its proper divisors (179680734).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

133605666 is a wasteful number, since it uses less digits than its factorization.

133605666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1240 (or 1234 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 36.

The square root of 133605666 is about 11558.7917188606. The cubic root of 133605666 is about 511.2205368769.

The spelling of 133605666 in words is "one hundred thirty-three million, six hundred five thousand, six hundred sixty-six".