1289393988 has 12 divisors (see below), whose sum is σ = 3008586000. Its totient is φ = 429797992.

The previous prime is 1289393957. The next prime is 1289393993. The reversal of 1289393988 is 8893939821.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53724738 + ... + 53724761.

It is an arithmetic number, because the mean of its divisors is an integer number (250715500).

Almost surely, 2^1289393988 is an apocalyptic number.

It is an amenable number.

1289393988 is an abundant number, since it is smaller than the sum of its proper divisors (1719192012).

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

1289393988 is a wasteful number, since it uses less digits than its factorization.

1289393988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107449506 (or 107449504 counting only the distinct ones).

The product of its digits is 6718464, while the sum is 60.

The square root of 1289393988 is about 35908.1326164422. The cubic root of 1289393988 is about 1088.4167424305.

The spelling of 1289393988 in words is "one billion, two hundred eighty-nine million, three hundred ninety-three thousand, nine hundred eighty-eight".