11577981517 has 4 divisors (see below), whose sum is σ = 11614505436. Its totient is φ = 11541457600.

The previous prime is 11577981491. The next prime is 11577981521. The reversal of 11577981517 is 71518977511.

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 5245960041 + 6332021476 = 72429^2 + 79574^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11577981517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11577981557) 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, 18261484 + ... + 18262117.

It is an arithmetic number, because the mean of its divisors is an integer number (2903626359).

Almost surely, 2^11577981517 is an apocalyptic number.

It is an amenable number.

11577981517 is a deficient number, since it is larger than the sum of its proper divisors (36523919).

11577981517 is an equidigital number, since it uses as much as digits as its factorization.

11577981517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36523918.

The product of its digits is 617400, while the sum is 52.

The spelling of 11577981517 in words is "eleven billion, five hundred seventy-seven million, nine hundred eighty-one thousand, five hundred seventeen".