2661665472 has 168 divisors, whose sum is σ = 7996123200. Its totient is φ = 845365248.

The previous prime is 2661665453. The next prime is 2661665473. The reversal of 2661665472 is 2745661662.

2661665472 is a `hidden beast` number, since 26 + 616 + 6 + 5 + 4 + 7 + 2 = 666.

It is not an unprimeable number, because it can be changed into a prime (2661665473) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1318608 + ... + 1320624.

Almost surely, 2^2661665472 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 2661665472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3998061600).

2661665472 is an abundant number, since it is smaller than the sum of its proper divisors (5334457728).

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

2661665472 is a wasteful number, since it uses less digits than its factorization.

2661665472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2143 (or 2130 counting only the distinct ones).

The product of its digits is 725760, while the sum is 45.

The square root of 2661665472 is about 51591.3313648718. The cubic root of 2661665472 is about 1385.8550975117.

The spelling of 2661665472 in words is "two billion, six hundred sixty-one million, six hundred sixty-five thousand, four hundred seventy-two".