13161261312440 has 64 divisors (see below), whose sum is σ = 30049963200000. Its totient is φ = 5186892350080.

The previous prime is 13161261312439. The next prime is 13161261312457. The reversal of 13161261312440 is 4421316216131.

13161261312440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×13161261312440³ (a number of 40 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 13161261312440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2711381 + ... + 5802939.

It is an arithmetic number, because the mean of its divisors is an integer number (469530675000).

Almost surely, 2^{13161261312440} is an apocalyptic number.

13161261312440 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 13161261312440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15024981600000).

13161261312440 is an abundant number, since it is smaller than the sum of its proper divisors (16888701887560).

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

13161261312440 is a wasteful number, since it uses less digits than its factorization.

13161261312440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3093140 (or 3093136 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 35.

Adding to 13161261312440 its reverse (4421316216131), we get a palindrome (17582577528571).

The spelling of 13161261312440 in words is "thirteen trillion, one hundred sixty-one billion, two hundred sixty-one million, three hundred twelve thousand, four hundred forty".