428319809 has 4 divisors (see below), whose sum is σ = 428498004. Its totient is φ = 428141616.

The previous prime is 428319803. The next prime is 428319877. The reversal of 428319809 is 908913824.

It is a happy number.

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 418079809 + 10240000 = 20447^2 + 3200^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-428319809 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 428319809.

It is not an unprimeable number, because it can be changed into a prime (428319803) 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, 85442 + ... + 90315.

It is an arithmetic number, because the mean of its divisors is an integer number (107124501).

Almost surely, 2^428319809 is an apocalyptic number.

It is an amenable number.

428319809 is a deficient number, since it is larger than the sum of its proper divisors (178195).

428319809 is a wasteful number, since it uses less digits than its factorization.

428319809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178194.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 428319809 is about 20695.8886979999. Note that the first 3 decimals coincide. The cubic root of 428319809 is about 753.7998616297.

The spelling of 428319809 in words is "four hundred twenty-eight million, three hundred nineteen thousand, eight hundred nine".