840389 has 8 divisors (see below), whose sum is σ = 965280. Its totient is φ = 723600.

The previous prime is 840353. The next prime is 840439. The reversal of 840389 is 983048.

840389 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 840389 - 2¹⁶ = 774853 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840319) 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, 1802 + ... + 2219.

It is an arithmetic number, because the mean of its divisors is an integer number (120660).

2⁸⁴⁰³⁸⁹ is an apocalyptic number.

It is an amenable number.

840389 is a deficient number, since it is larger than the sum of its proper divisors (124891).

840389 is a wasteful number, since it uses less digits than its factorization.

840389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4051.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 840389 is about 916.7273313260. The cubic root of 840389 is about 94.3684423027.

The spelling of 840389 in words is "eight hundred forty thousand, three hundred eighty-nine".