428561 has 4 divisors (see below), whose sum is σ = 489792. Its totient is φ = 367332.

The previous prime is 428557. The next prime is 428563. The reversal of 428561 is 165824.

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 not a de Polignac number, because 428561 - 2² = 428557 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 428561.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30605 + ... + 30618.

It is an arithmetic number, because the mean of its divisors is an integer number (122448).

2⁴²⁸⁵⁶¹ is an apocalyptic number.

It is an amenable number.

428561 is a deficient number, since it is larger than the sum of its proper divisors (61231).

428561 is an equidigital number, since it uses as much as digits as its factorization.

428561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61230.

The product of its digits is 1920, while the sum is 26.

The square root of 428561 is about 654.6457057065. The cubic root of 428561 is about 75.3941325728.

It can be divided in two parts, 428 and 561, that added together give a palindrome (989).

The spelling of 428561 in words is "four hundred twenty-eight thousand, five hundred sixty-one".