421428 has 48 divisors (see below), whose sum is σ = 1169280. Its totient is φ = 115584.

The previous prime is 421423. The next prime is 421433. The reversal of 421428 is 824124.

It is an interprime number because it is at equal distance from previous prime (421423) and next prime (421433).

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

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 421428.

It is not an unprimeable number, because it can be changed into a prime (421423) by changing a digit.

421428 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2350 + ... + 2522.

It is an arithmetic number, because the mean of its divisors is an integer number (24360).

2⁴²¹⁴²⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 421428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (584640).

421428 is an abundant number, since it is smaller than the sum of its proper divisors (747852).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

421428 is a wasteful number, since it uses less digits than its factorization.

421428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216 (or 214 counting only the distinct ones).

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

The square root of 421428 is about 649.1748608811. The cubic root of 421428 is about 74.9735017501.

The spelling of 421428 in words is "four hundred twenty-one thousand, four hundred twenty-eight".