900840 has 32 divisors (see below), whose sum is σ = 2702880. Its totient is φ = 240192.

The previous prime is 900821. The next prime is 900863. The reversal of 900840 is 48009.

It is an unprimeable number.

900840 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3634 + ... + 3873.

It is an arithmetic number, because the mean of its divisors is an integer number (84465).

2⁹⁰⁰⁸⁴⁰ is an apocalyptic number.

It is an amenable number.

900840 is an abundant number, since it is smaller than the sum of its proper divisors (1802040).

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

900840 is a wasteful number, since it uses less digits than its factorization.

900840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7521 (or 7517 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 900840 is about 949.1259136700. The cubic root of 900840 is about 96.5789665679.

Adding to 900840 its reverse (48009), we get a palindrome (948849).

The spelling of 900840 in words is "nine hundred thousand, eight hundred forty".