840423 has 8 divisors (see below), whose sum is σ = 1124848. Its totient is φ = 558144.

The previous prime is 840353. The next prime is 840439. The reversal of 840423 is 324048.

It is a happy number.

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

It is not a de Polignac number, because 840423 - 2⁹ = 839911 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 840423.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840473) 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, 1065 + ... + 1677.

It is an arithmetic number, because the mean of its divisors is an integer number (140606).

2⁸⁴⁰⁴²³ is an apocalyptic number.

840423 is a deficient number, since it is larger than the sum of its proper divisors (284425).

840423 is a wasteful number, since it uses less digits than its factorization.

840423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1073.

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 840423 is about 916.7458753657. The cubic root of 840423 is about 94.3697149212.

The spelling of 840423 in words is "eight hundred forty thousand, four hundred twenty-three".