420839 has 4 divisors (see below), whose sum is σ = 427800. Its totient is φ = 413880.

The previous prime is 420811. The next prime is 420851. The reversal of 420839 is 938024.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-420839 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3389 + ... + 3510.

It is an arithmetic number, because the mean of its divisors is an integer number (106950).

2⁴²⁰⁸³⁹ is an apocalyptic number.

420839 is a deficient number, since it is larger than the sum of its proper divisors (6961).

420839 is an equidigital number, since it uses as much as digits as its factorization.

420839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6960.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 420839 is about 648.7210494504. The cubic root of 420839 is about 74.9385570847.

It can be divided in two parts, 420 and 839, that multiplied together give a triangular number (352380 = T₈₃₉).

The spelling of 420839 in words is "four hundred twenty thousand, eight hundred thirty-nine".