13656617681 has 8 divisors (see below), whose sum is σ = 15768466560. Its totient is φ = 11584994688.

The previous prime is 13656617677. The next prime is 13656617693. The reversal of 13656617681 is 18671665631.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13656617681 - 2² = 13656617677 is a prime.

It is a super-2 number, since 2×13656617681² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13656617641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10055741 + ... + 10057098.

It is an arithmetic number, because the mean of its divisors is an integer number (1971058320).

Almost surely, 2^13656617681 is an apocalyptic number.

It is an amenable number.

13656617681 is a deficient number, since it is larger than the sum of its proper divisors (2111848879).

13656617681 is an equidigital number, since it uses as much as digits as its factorization.

13656617681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20112943.

The product of its digits is 1088640, while the sum is 50.

The spelling of 13656617681 in words is "thirteen billion, six hundred fifty-six million, six hundred seventeen thousand, six hundred eighty-one".