428921 has 4 divisors (see below), whose sum is σ = 430500. Its totient is φ = 427344.

The previous prime is 428899. The next prime is 428951. The reversal of 428921 is 129824.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 384400 + 44521 = 620^2 + 211^2 .

It is a cyclic number.

It is not a de Polignac number, because 428921 - 2¹⁴ = 412537 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 428921.

It is not an unprimeable number, because it can be changed into a prime (428951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266 + ... + 963.

It is an arithmetic number, because the mean of its divisors is an integer number (107625).

2⁴²⁸⁹²¹ is an apocalyptic number.

It is an amenable number.

428921 is a deficient number, since it is larger than the sum of its proper divisors (1579).

428921 is a wasteful number, since it uses less digits than its factorization.

428921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1578.

The product of its digits is 1152, while the sum is 26.

The square root of 428921 is about 654.9206058752. The cubic root of 428921 is about 75.4152375352.

The spelling of 428921 in words is "four hundred twenty-eight thousand, nine hundred twenty-one".