1328821 has 4 divisors (see below), whose sum is σ = 1431052. Its totient is φ = 1226592.

The previous prime is 1328807. The next prime is 1328827. The reversal of 1328821 is 1288231.

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 509796 + 819025 = 714^2 + 905^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1328821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1328827) 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, 51096 + ... + 51121.

It is an arithmetic number, because the mean of its divisors is an integer number (357763).

2^1328821 is an apocalyptic number.

It is an amenable number.

1328821 is a deficient number, since it is larger than the sum of its proper divisors (102231).

1328821 is a wasteful number, since it uses less digits than its factorization.

1328821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102230.

The product of its digits is 768, while the sum is 25.

The square root of 1328821 is about 1152.7449848080. The cubic root of 1328821 is about 109.9399396646.

The spelling of 1328821 in words is "one million, three hundred twenty-eight thousand, eight hundred twenty-one".