13181261544 has 640 divisors, whose sum is σ = 45050100480. Its totient is φ = 3558297600.

The previous prime is 13181261543. The next prime is 13181261551. The reversal of 13181261544 is 44516218131.

13181261544 is a `hidden beast` number, since 1 + 31 + 8 + 1 + 2 + 615 + 4 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 13181261499 and 13181261508.

It is not an unprimeable number, because it can be changed into a prime (13181261543) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 248703022 + ... + 248703074.

It is an arithmetic number, because the mean of its divisors is an integer number (70390782).

Almost surely, 2^13181261544 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 13181261544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22525050240).

13181261544 is an abundant number, since it is smaller than the sum of its proper divisors (31868838936).

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

13181261544 is a wasteful number, since it uses less digits than its factorization.

13181261544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183 (or 170 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

Adding to 13181261544 its reverse (44516218131), we get a palindrome (57697479675).

The spelling of 13181261544 in words is "thirteen billion, one hundred eighty-one million, two hundred sixty-one thousand, five hundred forty-four".