1000840 has 32 divisors (see below), whose sum is σ = 2280960. Its totient is φ = 395200.

The previous prime is 1000829. The next prime is 1000847. The reversal of 1000840 is 480001.

It is a self number, because there is not a number n which added to its sum of digits gives 1000840.

It is not an unprimeable number, because it can be changed into a prime (1000847) 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, 5145 + ... + 5335.

It is an arithmetic number, because the mean of its divisors is an integer number (71280).

2^1000840 is an apocalyptic number.

1000840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1000840 is an abundant number, since it is smaller than the sum of its proper divisors (1280120).

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

1000840 is a wasteful number, since it uses less digits than its factorization.

1000840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333 (or 329 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1000840 is about 1000.4199118370. The cubic root of 1000840 is about 100.0279921637.

Adding to 1000840 its reverse (480001), we get a palindrome (1480841).

The spelling of 1000840 in words is "one million, eight hundred forty", and thus it is an aban number.