13561660544 has 64 divisors (see below), whose sum is σ = 27646947000. Its totient is φ = 6624337920.

The previous prime is 13561660523. The next prime is 13561660547. The reversal of 13561660544 is 44506616531.

It can be written as a sum of positive squares in 4 ways, for example, as 6691240000 + 6870420544 = 81800^2 + 82888^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (13561660547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1157564 + ... + 1169220.

Almost surely, 2^13561660544 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13561660544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13823473500).

13561660544 is an abundant number, since it is smaller than the sum of its proper divisors (14085286456).

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

13561660544 is a wasteful number, since it uses less digits than its factorization.

13561660544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11881 (or 11869 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 41.

The spelling of 13561660544 in words is "thirteen billion, five hundred sixty-one million, six hundred sixty thousand, five hundred forty-four".