819421 has 6 divisors (see below), whose sum is σ = 857150. Its totient is φ = 783288.

The previous prime is 819419. The next prime is 819431. The reversal of 819421 is 124918.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 648025 + 171396 = 805^2 + 414^2 .

It is not a de Polignac number, because 819421 - 2¹ = 819419 is a prime.

It is a Duffinian number.

819421 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (819431) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 246 + ... + 1303.

2⁸¹⁹⁴²¹ is an apocalyptic number.

It is an amenable number.

819421 is a deficient number, since it is larger than the sum of its proper divisors (37729).

819421 is a wasteful number, since it uses less digits than its factorization.

819421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1595 (or 1572 counting only the distinct ones).

The product of its digits is 576, while the sum is 25.

The square root of 819421 is about 905.2187580911. The cubic root of 819421 is about 93.5769810319.

The spelling of 819421 in words is "eight hundred nineteen thousand, four hundred twenty-one".