2661388538112 has 144 divisors (see below), whose sum is σ = 7871354064000. Its totient is φ = 886998767616.

The previous prime is 2661388538093. The next prime is 2661388538191. The reversal of 2661388538112 is 2118358831662.

2661388538112 is a `hidden beast` number, since 2 + 6 + 6 + 13 + 88 + 538 + 1 + 12 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (54).

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, 54435214 + ... + 54484082.

It is an arithmetic number, because the mean of its divisors is an integer number (54662181000).

Almost surely, 2^{2661388538112} 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 2661388538112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3935677032000).

2661388538112 is an abundant number, since it is smaller than the sum of its proper divisors (5209965525888).

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

2661388538112 is an equidigital number, since it uses as much as digits as its factorization.

2661388538112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56773 (or 56753 counting only the distinct ones).

The product of its digits is 3317760, while the sum is 54.

The spelling of 2661388538112 in words is "two trillion, six hundred sixty-one billion, three hundred eighty-eight million, five hundred thirty-eight thousand, one hundred twelve".