11557728911556 has 81 divisors (see below), whose sum is σ = 29912868235341. Its totient is φ = 3762695934144.

The previous prime is 11557728911527. The next prime is 11557728911557. The reversal of 11557728911556 is 65511982775511.

The square root of 11557728911556 is 3399666.

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

11557728911556 is a `hidden beast` number, since 1 + 1 + 5 + 5 + 7 + 72 + 8 + 9 + 1 + 1 + 556 = 666.

It can be written as a sum of positive squares in only one way, i.e., 7457978664900 + 4099750246656 = 2730930^2 + 2024784^2 .

It is a super-2 number, since 2×11557728911556² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 11557728911493 and 11557728911502.

It is not an unprimeable number, because it can be changed into a prime (11557728911557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 877107240 + ... + 877120416.

Almost surely, 2^{11557728911556} is an apocalyptic number.

11557728911556 is the 3399666-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11557728911556

11557728911556 is an abundant number, since it is smaller than the sum of its proper divisors (18355139323785).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11557728911556 is an frugal number, since it uses more digits than its factorization.

11557728911556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26450 (or 13225 counting only the distinct ones).

The product of its digits is 26460000, while the sum is 63.

The spelling of 11557728911556 in words is "eleven trillion, five hundred fifty-seven billion, seven hundred twenty-eight million, nine hundred eleven thousand, five hundred fifty-six".