1288128644 has 24 divisors (see below), whose sum is σ = 2465779008. Its totient is φ = 583935840.

The previous prime is 1288128631. The next prime is 1288128679. The reversal of 1288128644 is 4468218821.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a junction number, because it is equal to n+sod(n) for n = 1288128595 and 1288128604.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22832 + ... + 55655.

It is an arithmetic number, because the mean of its divisors is an integer number (102740792).

Almost surely, 2^1288128644 is an apocalyptic number.

It is an amenable number.

1288128644 is a deficient number, since it is larger than the sum of its proper divisors (1177650364).

1288128644 is a wasteful number, since it uses less digits than its factorization.

1288128644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78875 (or 78873 counting only the distinct ones).

The product of its digits is 196608, while the sum is 44.

The square root of 1288128644 is about 35890.5091075621. The cubic root of 1288128644 is about 1088.0605874294.

The spelling of 1288128644 in words is "one billion, two hundred eighty-eight million, one hundred twenty-eight thousand, six hundred forty-four".