128248786708561 has 4 divisors (see below), whose sum is σ = 128253036060724. Its totient is φ = 128244537356400.

The previous prime is 128248786708487. The next prime is 128248786708571. The reversal of 128248786708561 is 165807687842821.

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 71755824916161 + 56492961792400 = 8470881^2 + 7516180^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128248786708561 is a prime.

It is a super-3 number, since 3×128248786708561³ (a number of 43 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128248786708571) 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, 2124630810 + ... + 2124691171.

It is an arithmetic number, because the mean of its divisors is an integer number (32063259015181).

Almost surely, 2^{128248786708561} is an apocalyptic number.

It is an amenable number.

128248786708561 is a deficient number, since it is larger than the sum of its proper divisors (4249352163).

128248786708561 is an equidigital number, since it uses as much as digits as its factorization.

128248786708561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4249352162.

The product of its (nonzero) digits is 578027520, while the sum is 73.

The spelling of 128248786708561 in words is "one hundred twenty-eight trillion, two hundred forty-eight billion, seven hundred eighty-six million, seven hundred eight thousand, five hundred sixty-one".