428021 has 8 divisors (see below), whose sum is σ = 471744. Its totient is φ = 385120.

The previous prime is 428003. The next prime is 428023. The reversal of 428021 is 120824.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 428021 - 2⁶ = 427957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1721 + ... + 1953.

It is an arithmetic number, because the mean of its divisors is an integer number (58968).

2⁴²⁸⁰²¹ is an apocalyptic number.

It is an amenable number.

428021 is a deficient number, since it is larger than the sum of its proper divisors (43723).

428021 is a wasteful number, since it uses less digits than its factorization.

428021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411.

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 428021 is about 654.2331388733. The cubic root of 428021 is about 75.3624529571.

Adding to 428021 its reverse (120824), we get a palindrome (548845).

The spelling of 428021 in words is "four hundred twenty-eight thousand, twenty-one".