2728287666 has 72 divisors (see below), whose sum is σ = 6424927236. Its totient is φ = 836334720.

The previous prime is 2728287629. The next prime is 2728287671. The reversal of 2728287666 is 6667828272.

It can be written as a sum of positive squares in 6 ways, for example, as 1816549641 + 911738025 = 42621^2 + 30195^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 889776 + ... + 892836.

Almost surely, 2^2728287666 is an apocalyptic number.

2728287666 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 2728287666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3212463618).

2728287666 is an abundant number, since it is smaller than the sum of its proper divisors (3696639570).

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

2728287666 is a wasteful number, since it uses less digits than its factorization.

2728287666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3388 (or 3372 counting only the distinct ones).

The product of its digits is 5419008, while the sum is 54.

The square root of 2728287666 is about 52233.0131813205. The cubic root of 2728287666 is about 1397.3227177314.

The spelling of 2728287666 in words is "two billion, seven hundred twenty-eight million, two hundred eighty-seven thousand, six hundred sixty-six".