11856986505 has 48 divisors (see below), whose sum is σ = 25294913280. Its totient is φ = 5003385984.

The previous prime is 11856986417. The next prime is 11856986543. The reversal of 11856986505 is 50568965811.

11856986505 is a `hidden beast` number, since 1 + 1 + 8 + 56 + 9 + 86 + 505 = 666.

It is not a de Polignac number, because 11856986505 - 2¹² = 11856982409 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1443645 + ... + 1451834.

It is an arithmetic number, because the mean of its divisors is an integer number (526977360).

Almost surely, 2^11856986505 is an apocalyptic number.

11856986505 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

11856986505 is an abundant number, since it is smaller than the sum of its proper divisors (13437926775).

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

11856986505 is a wasteful number, since it uses less digits than its factorization.

11856986505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2895510 (or 2895507 counting only the distinct ones).

The product of its (nonzero) digits is 2592000, while the sum is 54.

The spelling of 11856986505 in words is "eleven billion, eight hundred fifty-six million, nine hundred eighty-six thousand, five hundred five".