1287128728 has 8 divisors (see below), whose sum is σ = 2413366380. Its totient is φ = 643564360.

The previous prime is 1287128707. The next prime is 1287128747. The reversal of 1287128728 is 8278217821.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80445538 + ... + 80445553.

Almost surely, 2^1287128728 is an apocalyptic number.

It is an amenable number.

1287128728 is a deficient number, since it is larger than the sum of its proper divisors (1126237652).

1287128728 is a wasteful number, since it uses less digits than its factorization.

1287128728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160891097 (or 160891093 counting only the distinct ones).

The product of its digits is 200704, while the sum is 46.

The square root of 1287128728 is about 35876.5763138012. The cubic root of 1287128728 is about 1087.7789771439.

The spelling of 1287128728 in words is "one billion, two hundred eighty-seven million, one hundred twenty-eight thousand, seven hundred twenty-eight".