133640 has 32 divisors (see below), whose sum is σ = 325080. Its totient is φ = 49152.

The previous prime is 133633. The next prime is 133649. The reversal of 133640 is 46331.

It can be written as a sum of positive squares in 4 ways, for example, as 119716 + 13924 = 346^2 + 118^2 .

It is not an unprimeable number, because it can be changed into a prime (133649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 392 + ... + 648.

2¹³³⁶⁴⁰ is an apocalyptic number.

133640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 133640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (162540).

133640 is an abundant number, since it is smaller than the sum of its proper divisors (191440).

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

133640 is a wasteful number, since it uses less digits than its factorization.

133640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281 (or 277 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 133640 is about 365.5680511204. The cubic root of 133640 is about 51.1264324298.

Adding to 133640 its reverse (46331), we get a palindrome (179971).

The spelling of 133640 in words is "one hundred thirty-three thousand, six hundred forty".