13605565680 has 320 divisors, whose sum is σ = 53975116800. Its totient is φ = 3085655040.

The previous prime is 13605565663. The next prime is 13605565709. The reversal of 13605565680 is 8656550631.

13605565680 is a `hidden beast` number, since 1 + 3 + 6 + 0 + 5 + 565 + 6 + 80 = 666.

It is a super-2 number, since 2×13605565680² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1977286 + ... + 1984154.

It is an arithmetic number, because the mean of its divisors is an integer number (168672240).

Almost surely, 2^13605565680 is an apocalyptic number.

13605565680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13605565680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26987558400).

13605565680 is an abundant number, since it is smaller than the sum of its proper divisors (40369551120).

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

13605565680 is a wasteful number, since it uses less digits than its factorization.

13605565680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7029 (or 7017 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 45.

The spelling of 13605565680 in words is "thirteen billion, six hundred five million, five hundred sixty-five thousand, six hundred eighty".