2661881568 has 96 divisors (see below), whose sum is σ = 7063056000. Its totient is φ = 877754880.

The previous prime is 2661881567. The next prime is 2661881587. The reversal of 2661881568 is 8651881662.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×2661881568² = 14171226964116277248, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2661881568.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2661881561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5334183 + ... + 5334681.

It is an arithmetic number, because the mean of its divisors is an integer number (73573500).

Almost surely, 2^2661881568 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 2661881568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3531528000).

2661881568 is an abundant number, since it is smaller than the sum of its proper divisors (4401174432).

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

2661881568 is a wasteful number, since it uses less digits than its factorization.

2661881568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000 (or 992 counting only the distinct ones).

The product of its digits is 1105920, while the sum is 51.

The square root of 2661881568 is about 51593.4256276902. The cubic root of 2661881568 is about 1385.8926015534.

The spelling of 2661881568 in words is "two billion, six hundred sixty-one million, eight hundred eighty-one thousand, five hundred sixty-eight".