840140 has 48 divisors (see below), whose sum is σ = 2140992. Its totient is φ = 270336.

The previous prime is 840139. The next prime is 840149. The reversal of 840140 is 41048.

It is a happy number.

840140 is nontrivially palindromic in base 13.

840140 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is not an unprimeable number, because it can be changed into a prime (840149) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2204 + ... + 2556.

It is an arithmetic number, because the mean of its divisors is an integer number (44604).

2⁸⁴⁰¹⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 840140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1070496).

840140 is an abundant number, since it is smaller than the sum of its proper divisors (1300852).

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

840140 is a wasteful number, since it uses less digits than its factorization.

840140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386 (or 384 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 840140 is about 916.5915120707. The cubic root of 840140 is about 94.3591211973.

Adding to 840140 its reverse (41048), we get a palindrome (881188).

The spelling of 840140 in words is "eight hundred forty thousand, one hundred forty".