428421 has 16 divisors (see below), whose sum is σ = 681984. Its totient is φ = 233904.

The previous prime is 428411. The next prime is 428429. The reversal of 428421 is 124824.

It is not a de Polignac number, because 428421 - 2¹⁴ = 412037 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428429) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40 + ... + 926.

It is an arithmetic number, because the mean of its divisors is an integer number (42624).

2⁴²⁸⁴²¹ is an apocalyptic number.

It is an amenable number.

428421 is a deficient number, since it is larger than the sum of its proper divisors (253563).

428421 is a wasteful number, since it uses less digits than its factorization.

428421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 920.

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

The square root of 428421 is about 654.5387689052. The cubic root of 428421 is about 75.3859218956.

The spelling of 428421 in words is "four hundred twenty-eight thousand, four hundred twenty-one".