1328681 has 4 divisors (see below), whose sum is σ = 1343700. Its totient is φ = 1313664.

The previous prime is 1328671. The next prime is 1328683. The reversal of 1328681 is 1868231.

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 714025 + 614656 = 845^2 + 784^2 .

It is a cyclic number.

It is not a de Polignac number, because 1328681 - 2⁶ = 1328617 is a prime.

It is a super-2 number, since 2×1328681² = 3530786399522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1328683) 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, 7376 + ... + 7553.

It is an arithmetic number, because the mean of its divisors is an integer number (335925).

2^1328681 is an apocalyptic number.

It is an amenable number.

1328681 is a deficient number, since it is larger than the sum of its proper divisors (15019).

1328681 is an equidigital number, since it uses as much as digits as its factorization.

1328681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15018.

The product of its digits is 2304, while the sum is 29.

The square root of 1328681 is about 1152.6842585895. The cubic root of 1328681 is about 109.9360785647.

The spelling of 1328681 in words is "one million, three hundred twenty-eight thousand, six hundred eighty-one".