11640 has 32 divisors (see below), whose sum is σ = 35280. Its totient is φ = 3072.

The previous prime is 11633. The next prime is 11657. The reversal of 11640 is 4611.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a nialpdrome in base 11.

It is a zygodrome in base 11.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72 + ... + 168.

2¹¹⁶⁴⁰ is an apocalyptic number.

11640 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 11640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17640).

11640 is an abundant number, since it is smaller than the sum of its proper divisors (23640).

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

11640 is a wasteful number, since it uses less digits than its factorization.

11640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111 (or 107 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 11640 is about 107.8888316741. Note that the first 4 decimals coincide. The cubic root of 11640 is about 22.6630136366.

Subtracting from 11640 its sum of digits (12), we obtain a triangular number (11628 = T₁₅₂).

Adding to 11640 its product of nonzero digits (24), we get a square (11664 = 108²).

The spelling of 11640 in words is "eleven thousand, six hundred forty".