2728808645 has 8 divisors (see below), whose sum is σ = 3363072504. Its totient is φ = 2124045504.

The previous prime is 2728808623. The next prime is 2728808659. The reversal of 2728808645 is 5468088272.

It is a happy number.

It is a Cunningham number, because it is equal to 52238²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 259016836 + 2469791809 = 16094^2 + 49697^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2728808645 - 2¹⁰ = 2728807621 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2728808593 and 2728808602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7374974 + ... + 7375343.

It is an arithmetic number, because the mean of its divisors is an integer number (420384063).

Almost surely, 2^2728808645 is an apocalyptic number.

It is an amenable number.

2728808645 is a deficient number, since it is larger than the sum of its proper divisors (634263859).

2728808645 is a wasteful number, since it uses less digits than its factorization.

2728808645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14750359.

The product of its (nonzero) digits is 1720320, while the sum is 50.

The square root of 2728808645 is about 52238.0000095716. Note that the first 5 decimals coincide. The cubic root of 2728808645 is about 1397.4116537907.

The spelling of 2728808645 in words is "two billion, seven hundred twenty-eight million, eight hundred eight thousand, six hundred forty-five".