1028640 has 48 divisors (see below), whose sum is σ = 3241728. Its totient is φ = 274176.

The previous prime is 1028617. The next prime is 1028647. The reversal of 1028640 is 468201.

It is a tau number, because it is divible by the number of its divisors (48).

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (1028647) 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, 592 + ... + 1551.

It is an arithmetic number, because the mean of its divisors is an integer number (67536).

2^1028640 is an apocalyptic number.

1028640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1028640 is an abundant number, since it is smaller than the sum of its proper divisors (2213088).

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

1028640 is a wasteful number, since it uses less digits than its factorization.

1028640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2161 (or 2153 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 1028640 is about 1014.2189112810. The cubic root of 1028640 is about 100.9456950824.

The spelling of 1028640 in words is "one million, twenty-eight thousand, six hundred forty".