457821 has 36 divisors (see below), whose sum is σ = 837408. Its totient is φ = 235872.

The previous prime is 457817. The next prime is 457829. The reversal of 457821 is 128754.

457821 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 457821 - 2² = 457817 is a prime.

457821 is strictly pandigital in base 7.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (457829) 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 35 ways as a sum of consecutive naturals, for example, 10626 + ... + 10668.

2⁴⁵⁷⁸²¹ is an apocalyptic number.

It is an amenable number.

457821 is a deficient number, since it is larger than the sum of its proper divisors (379587).

457821 is a wasteful number, since it uses less digits than its factorization.

457821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82 (or 66 counting only the distinct ones).

The product of its digits is 2240, while the sum is 27.

The square root of 457821 is about 676.6247113430. The cubic root of 457821 is about 77.0723444444.

The spelling of 457821 in words is "four hundred fifty-seven thousand, eight hundred twenty-one".