840023 has 2 divisors, whose sum is σ = 840024. Its totient is φ = 840022.

The previous prime is 839999. The next prime is 840053. The reversal of 840023 is 320048.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 840023 - 2⁶ = 839959 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 839983 and 840010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420011 + 420012.

It is an arithmetic number, because the mean of its divisors is an integer number (420012).

2⁸⁴⁰⁰²³ is an apocalyptic number.

840023 is a deficient number, since it is larger than the sum of its proper divisors (1).

840023 is an equidigital number, since it uses as much as digits as its factorization.

840023 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 840023 is about 916.5276864340. The cubic root of 840023 is about 94.3547407648.

The spelling of 840023 in words is "eight hundred forty thousand, twenty-three".