133440 has 56 divisors (see below), whose sum is σ = 426720. Its totient is φ = 35328.

The previous prime is 133439. The next prime is 133447. The reversal of 133440 is 44331.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133447) 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, 891 + ... + 1029.

It is an arithmetic number, because the mean of its divisors is an integer number (7620).

2¹³³⁴⁴⁰ is an apocalyptic number.

133440 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 133440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (213360).

133440 is an abundant number, since it is smaller than the sum of its proper divisors (293280).

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

133440 is a wasteful number, since it uses less digits than its factorization.

133440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 133440 is about 365.2944018186. The cubic root of 133440 is about 51.1009151404.

Adding to 133440 its reverse (44331), we get a palindrome (177771).

The spelling of 133440 in words is "one hundred thirty-three thousand, four hundred forty".