1328499821681 has 16 divisors (see below), whose sum is σ = 1361341416960. Its totient is φ = 1296110587200.

The previous prime is 1328499821651. The next prime is 1328499821683. The reversal of 1328499821681 is 1861289948231.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1328499821681 is a prime.

It is a super-2 number, since 2×1328499821681² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1328499821683) 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 in 15 ways as a sum of consecutive naturals, for example, 3847931 + ... + 4178943.

It is an arithmetic number, because the mean of its divisors is an integer number (85083838560).

Almost surely, 2^{1328499821681} is an apocalyptic number.

It is an amenable number.

1328499821681 is a deficient number, since it is larger than the sum of its proper divisors (32841595279).

1328499821681 is a wasteful number, since it uses less digits than its factorization.

1328499821681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331696.

The product of its digits is 11943936, while the sum is 62.

The spelling of 1328499821681 in words is "one trillion, three hundred twenty-eight billion, four hundred ninety-nine million, eight hundred twenty-one thousand, six hundred eighty-one".