840280 has 32 divisors (see below), whose sum is σ = 2161440. Its totient is φ = 288000.

The previous prime is 840277. The next prime is 840289. The reversal of 840280 is 82048.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840289) 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, 1221 + ... + 1780.

It is an arithmetic number, because the mean of its divisors is an integer number (67545).

2⁸⁴⁰²⁸⁰ is an apocalyptic number.

It is an amenable number.

840280 is an abundant number, since it is smaller than the sum of its proper divisors (1321160).

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

840280 is a wasteful number, since it uses less digits than its factorization.

840280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3019 (or 3015 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 22.

The square root of 840280 is about 916.6678787871. The cubic root of 840280 is about 94.3643622061.

The spelling of 840280 in words is "eight hundred forty thousand, two hundred eighty".