1328640 has 80 divisors (see below), whose sum is σ = 4272048. Its totient is φ = 352256.

The previous prime is 1328617. The next prime is 1328647. The reversal of 1328640 is 468231.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1328640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1328647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7594 + ... + 7766.

2^1328640 is an apocalyptic number.

1328640 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 1328640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2136024).

1328640 is an abundant number, since it is smaller than the sum of its proper divisors (2943408).

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

1328640 is an equidigital number, since it uses as much as digits as its factorization.

1328640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199 (or 183 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 1328640 is about 1152.6664738770. Note that the first 3 decimals coincide. The cubic root of 1328640 is about 109.9349477626.

The spelling of 1328640 in words is "one million, three hundred twenty-eight thousand, six hundred forty".