424821 has 16 divisors (see below), whose sum is σ = 619200. Its totient is φ = 258048.

The previous prime is 424819. The next prime is 424829. The reversal of 424821 is 128424.

It is not a de Polignac number, because 424821 - 2¹ = 424819 is a prime.

It is an Ulam number.

424821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (424829) 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 15 ways as a sum of consecutive naturals, for example, 1525 + ... + 1781.

It is an arithmetic number, because the mean of its divisors is an integer number (38700).

2⁴²⁴⁸²¹ is an apocalyptic number.

It is an amenable number.

424821 is a deficient number, since it is larger than the sum of its proper divisors (194379).

424821 is a wasteful number, since it uses less digits than its factorization.

424821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308.

The product of its digits is 512, while the sum is 21.

The square root of 424821 is about 651.7829393287. The cubic root of 424821 is about 75.1741729816.

The spelling of 424821 in words is "four hundred twenty-four thousand, eight hundred twenty-one".