1005840 has 120 divisors (see below), whose sum is σ = 3714048. Its totient is φ = 241920.

The previous prime is 1005833. The next prime is 1005883. The reversal of 1005840 is 485001.

Added to its reverse (485001) it gives a square (1490841 = 1221²).

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7857 + ... + 7983.

2^1005840 is an apocalyptic number.

1005840 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 1005840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1857024).

1005840 is an abundant number, since it is smaller than the sum of its proper divisors (2708208).

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

1005840 is a wasteful number, since it uses less digits than its factorization.

1005840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 1005840 is about 1002.9157492033. The cubic root of 1005840 is about 100.1942889403.

Adding to 1005840 its reverse (485001), we get a square (1490841 = 1221²).

The spelling of 1005840 in words is "one million, five thousand, eight hundred forty".