11581117506387 has 72 divisors (see below), whose sum is σ = 19823133861648. Its totient is φ = 6458505580800.

The previous prime is 11581117506379. The next prime is 11581117506397. The reversal of 11581117506387 is 78360571118511.

It is a happy number.

11581117506387 is a `hidden beast` number, since 1 + 1 + 58 + 1 + 1 + 1 + 7 + 506 + 3 + 87 = 666.

It is not a de Polignac number, because 11581117506387 - 2³ = 11581117506379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11581117506337) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 4211937 + ... + 6395517.

It is an arithmetic number, because the mean of its divisors is an integer number (275321303634).

Almost surely, 2^{11581117506387} is an apocalyptic number.

11581117506387 is a deficient number, since it is larger than the sum of its proper divisors (8242016355261).

11581117506387 is a wasteful number, since it uses less digits than its factorization.

11581117506387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2183941 (or 2183925 counting only the distinct ones).

The product of its (nonzero) digits is 1411200, while the sum is 54.

The spelling of 11581117506387 in words is "eleven trillion, five hundred eighty-one billion, one hundred seventeen million, five hundred six thousand, three hundred eighty-seven".