421789 has 4 divisors (see below), whose sum is σ = 424000. Its totient is φ = 419580.

The previous prime is 421783. The next prime is 421801. The reversal of 421789 is 987124.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 421789 - 2⁷ = 421661 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 421789.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421783) 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, 789 + ... + 1210.

It is an arithmetic number, because the mean of its divisors is an integer number (106000).

2⁴²¹⁷⁸⁹ is an apocalyptic number.

It is an amenable number.

421789 is a deficient number, since it is larger than the sum of its proper divisors (2211).

421789 is a wasteful number, since it uses less digits than its factorization.

421789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2210.

The product of its digits is 4032, while the sum is 31.

The square root of 421789 is about 649.4528466332. The cubic root of 421789 is about 74.9949033574.

The spelling of 421789 in words is "four hundred twenty-one thousand, seven hundred eighty-nine".