427821 has 4 divisors (see below), whose sum is σ = 570432. Its totient is φ = 285212.

The previous prime is 427813. The next prime is 427849. The reversal of 427821 is 128724.

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 427821 - 2³ = 427813 is a prime.

It is an Ulam number.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 427791 and 427800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (427421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71301 + ... + 71306.

It is an arithmetic number, because the mean of its divisors is an integer number (142608).

2⁴²⁷⁸²¹ is an apocalyptic number.

It is an amenable number.

427821 is a deficient number, since it is larger than the sum of its proper divisors (142611).

427821 is a wasteful number, since it uses less digits than its factorization.

427821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142610.

The product of its digits is 896, while the sum is 24.

The square root of 427821 is about 654.0802703033. The cubic root of 427821 is about 75.3507130044.

The spelling of 427821 in words is "four hundred twenty-seven thousand, eight hundred twenty-one".