11638640 has 120 divisors (see below), whose sum is σ = 31747968. Its totient is φ = 3939840.

The previous prime is 11638639. The next prime is 11638643. The reversal of 11638640 is 4683611.

11638640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11638643) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 375425 + ... + 375455.

Almost surely, 2^11638640 is an apocalyptic number.

11638640 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 11638640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15873984).

11638640 is an abundant number, since it is smaller than the sum of its proper divisors (20109328).

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

11638640 is a wasteful number, since it uses less digits than its factorization.

11638640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 70 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 11638640 is about 3411.5451044944. The cubic root of 11638640 is about 226.6213096480.

The spelling of 11638640 in words is "eleven million, six hundred thirty-eight thousand, six hundred forty".