428821689 has 4 divisors (see below), whose sum is σ = 571762256. Its totient is φ = 285881124.

The previous prime is 428821661. The next prime is 428821691. The reversal of 428821689 is 986128824.

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 428821689 - 2¹¹ = 428819641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (428821609) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71470279 + ... + 71470284.

It is an arithmetic number, because the mean of its divisors is an integer number (142940564).

Almost surely, 2^428821689 is an apocalyptic number.

It is an amenable number.

428821689 is a deficient number, since it is larger than the sum of its proper divisors (142940567).

428821689 is a wasteful number, since it uses less digits than its factorization.

428821689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142940566.

The product of its digits is 442368, while the sum is 48.

The square root of 428821689 is about 20708.0102617321. The cubic root of 428821689 is about 754.0941661808.

The spelling of 428821689 in words is "four hundred twenty-eight million, eight hundred twenty-one thousand, six hundred eighty-nine".