1328897681 has 2 divisors, whose sum is σ = 1328897682. Its totient is φ = 1328897680.

The previous prime is 1328897641. The next prime is 1328897683. The reversal of 1328897681 is 1867988231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 711822400 + 617075281 = 26680^2 + 24841^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1328897681 is a prime.

It is a super-2 number, since 2×1328897681² = 3531938093134355522, which contains 22 as substring.

Together with 1328897683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1328897683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 664448840 + 664448841.

It is an arithmetic number, because the mean of its divisors is an integer number (664448841).

Almost surely, 2^1328897681 is an apocalyptic number.

It is an amenable number.

1328897681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1328897681 is an equidigital number, since it uses as much as digits as its factorization.

1328897681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1161216, while the sum is 53.

The square root of 1328897681 is about 36454.0488972076. The cubic root of 1328897681 is about 1099.4205435687.

The spelling of 1328897681 in words is "one billion, three hundred twenty-eight million, eight hundred ninety-seven thousand, six hundred eighty-one".