1001000 has 128 divisors (see below), whose sum is σ = 3144960. Its totient is φ = 288000.

The previous prime is 1000999. The next prime is 1001003. The reversal of 1001000 is 1001.

Added to its reverse (1001) it gives a square (1002001 = 1001²).

It is a sliding number, since 1001000 = 1000 + 1000000 and 1/1000 + 1/1000000 = 0.001001000.

It is a Harshad number since it is a multiple of its sum of digits (2).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001003) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 76994 + ... + 77006.

It is an arithmetic number, because the mean of its divisors is an integer number (24570).

2^1001000 is an apocalyptic number.

1001000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a pronic number, being equal to 1000×1001.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1001000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1572480).

1001000 is an abundant number, since it is smaller than the sum of its proper divisors (2143960).

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

1001000 is a wasteful number, since it uses less digits than its factorization.

1001000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 1, while the sum is 2.

The square root of 1001000 is about 1000.4998750625. The cubic root of 1001000 is about 100.0333222284.

Adding to 1001000 its reverse (1001), we get a palindrome (1002001).

Subtracting from 1001000 its reverse (1001), we obtain a palindrome (999999).

1001000 divided by its reverse (1001) gives a cube (1000 = 10³).

The spelling of 1001000 in words is "one million, one thousand".