2728781661168 has 60 divisors (see below), whose sum is σ = 8086022135568. Its totient is φ = 856088363520.

The previous prime is 2728781661139. The next prime is 2728781661169. The reversal of 2728781661168 is 8611661878272.

It is a happy number.

2728781661168 is a `hidden beast` number, since 2 + 7 + 2 + 8 + 7 + 8 + 1 + 6 + 611 + 6 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2728781661169) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 557346748 + ... + 557351643.

Almost surely, 2^{2728781661168} is an apocalyptic number.

It is an amenable number.

2728781661168 is an abundant number, since it is smaller than the sum of its proper divisors (5357240474400).

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

2728781661168 is a wasteful number, since it uses less digits than its factorization.

2728781661168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1114698422 (or 1114698413 counting only the distinct ones).

The product of its digits is 21676032, while the sum is 63.

The spelling of 2728781661168 in words is "two trillion, seven hundred twenty-eight billion, seven hundred eighty-one million, six hundred sixty-one thousand, one hundred sixty-eight".