840340 has 12 divisors (see below), whose sum is σ = 1764756. Its totient is φ = 336128.

The previous prime is 840331. The next prime is 840341. The reversal of 840340 is 43048.

It can be written as a sum of positive squares in 2 ways, for example, as 197136 + 643204 = 444^2 + 802^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20989 + ... + 21028.

It is an arithmetic number, because the mean of its divisors is an integer number (147063).

2⁸⁴⁰³⁴⁰ is an apocalyptic number.

It is an amenable number.

840340 is an abundant number, since it is smaller than the sum of its proper divisors (924416).

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

840340 is a wasteful number, since it uses less digits than its factorization.

840340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42026 (or 42024 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 840340 is about 916.7006054323. The cubic root of 840340 is about 94.3666081745.

Adding to 840340 its reverse (43048), we get a palindrome (883388).

The spelling of 840340 in words is "eight hundred forty thousand, three hundred forty".