11985181656 has 48 divisors (see below), whose sum is σ = 34854868440. Its totient is φ = 3424337280.

The previous prime is 11985181609. The next prime is 11985181727. The reversal of 11985181656 is 65618158911.

It is a junction number, because it is equal to n+sod(n) for n = 11985181599 and 11985181608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5094565 + ... + 5096916.

Almost surely, 2^11985181656 is an apocalyptic number.

It is an amenable number.

11985181656 is an abundant number, since it is smaller than the sum of its proper divisors (22869686784).

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

11985181656 is a wasteful number, since it uses less digits than its factorization.

11985181656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10191504 (or 10191493 counting only the distinct ones).

The product of its digits is 518400, while the sum is 51.

The spelling of 11985181656 in words is "eleven billion, nine hundred eighty-five million, one hundred eighty-one thousand, six hundred fifty-six".