660205728 has 336 divisors, whose sum is σ = 2406208896. Its totient is φ = 173560320.

The previous prime is 660205723. The next prime is 660205747. The reversal of 660205728 is 827502066.

660205728 is a `hidden beast` number, since 6 + 60 + 20 + 572 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 660205692 and 660205701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660205723) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 2122693 + ... + 2123003.

It is an arithmetic number, because the mean of its divisors is an integer number (7161336).

Almost surely, 2^660205728 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 660205728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1203104448).

660205728 is an abundant number, since it is smaller than the sum of its proper divisors (1746003168).

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

660205728 is a wasteful number, since it uses less digits than its factorization.

660205728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359 (or 336 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 660205728 is about 25694.4688211296. The cubic root of 660205728 is about 870.7492238040.

The spelling of 660205728 in words is "six hundred sixty million, two hundred five thousand, seven hundred twenty-eight".