6660526720 has 64 divisors (see below), whose sum is σ = 15966082440. Its totient is φ = 2656972800.

The previous prime is 6660526687. The next prime is 6660526721. The reversal of 6660526720 is 276250666.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6383370816 + 277155904 = 79896^2 + 16648^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (6660526721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 224770 + ... + 252670.

Almost surely, 2^6660526720 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 6660526720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7983041220).

6660526720 is an abundant number, since it is smaller than the sum of its proper divisors (9305555720).

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

6660526720 is a wasteful number, since it uses less digits than its factorization.

6660526720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28293 (or 28281 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 40.

The square root of 6660526720 is about 81612.0500906576. The cubic root of 6660526720 is about 1881.4940891880.

The spelling of 6660526720 in words is "six billion, six hundred sixty million, five hundred twenty-six thousand, seven hundred twenty".