128826131557 has 4 divisors (see below), whose sum is σ = 128914795180. Its totient is φ = 128737467936.

The previous prime is 128826131549. The next prime is 128826131579. The reversal of 128826131557 is 755131628821.

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 127430436676 + 1395694881 = 356974^2 + 37359^2 .

It is a cyclic number.

It is not a de Polignac number, because 128826131557 - 2³ = 128826131549 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128826131557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128826131537) 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, 44329632 + ... + 44332537.

It is an arithmetic number, because the mean of its divisors is an integer number (32228698795).

Almost surely, 2^128826131557 is an apocalyptic number.

It is an amenable number.

128826131557 is a deficient number, since it is larger than the sum of its proper divisors (88663623).

128826131557 is an equidigital number, since it uses as much as digits as its factorization.

128826131557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88663622.

The product of its digits is 806400, while the sum is 49.

The spelling of 128826131557 in words is "one hundred twenty-eight billion, eight hundred twenty-six million, one hundred thirty-one thousand, five hundred fifty-seven".