33640 has 24 divisors (see below), whose sum is σ = 78390. Its totient is φ = 12992.

The previous prime is 33637. The next prime is 33641. The reversal of 33640 is 4633.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 27556 + 6084 = 166^2 + 78^2 .

It is a super-2 number, since 2×33640² = 2263299200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (33641) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1146 + ... + 1174.

2³³⁶⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 33640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39195).

33640 is an abundant number, since it is smaller than the sum of its proper divisors (44750).

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

33640 is a wasteful number, since it uses less digits than its factorization.

33640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69 (or 36 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 16.

The square root of 33640 is about 183.4121042898. The cubic root of 33640 is about 32.2813728318.

Adding to 33640 its product of nonzero digits (216), we get a square (33856 = 184²).

The spelling of 33640 in words is "thirty-three thousand, six hundred forty".