128809927801 has 3 divisors (see below), whose sum is σ = 128810286703. Its totient is φ = 128809568900.

The previous prime is 128809927783. The next prime is 128809927817. The reversal of 128809927801 is 108729908821.

The square root of 128809927801 is 358901.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 108729908821 = 7481 ⋅14534141.

It can be written as a sum of positive squares in only one way, i.e., 128666407401 + 143520400 = 358701^2 + 11980^2 .

It is not a de Polignac number, because 128809927801 - 2¹¹ = 128809925753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128809927201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 179451 + ... + 538351.

Almost surely, 2^128809927801 is an apocalyptic number.

128809927801 is the 358901-st square number.

128809927801 is the 179451-st centered octagonal number.

It is an amenable number.

128809927801 is a deficient number, since it is larger than the sum of its proper divisors (358902).

128809927801 is an frugal number, since it uses more digits than its factorization.

128809927801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 717802 (or 358901 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 55.

The spelling of 128809927801 in words is "one hundred twenty-eight billion, eight hundred nine million, nine hundred twenty-seven thousand, eight hundred one".