1288139984 has 30 divisors (see below), whose sum is σ = 2543838486. Its totient is φ = 631895680.

The previous prime is 1288139981. The next prime is 1288139999. The reversal of 1288139984 is 4899318821.

It can be written as a sum of positive squares in 3 ways, for example, as 858490000 + 429649984 = 29300^2 + 20728^2 .

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1288139981) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 30614 + ... + 59274.

Almost surely, 2^1288139984 is an apocalyptic number.

It is an amenable number.

1288139984 is a deficient number, since it is larger than the sum of its proper divisors (1255698502).

1288139984 is an equidigital number, since it uses as much as digits as its factorization.

1288139984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28775 (or 28716 counting only the distinct ones).

The product of its digits is 995328, while the sum is 53.

The square root of 1288139984 is about 35890.6670876984. The cubic root of 1288139984 is about 1088.0637803224.

The spelling of 1288139984 in words is "one billion, two hundred eighty-eight million, one hundred thirty-nine thousand, nine hundred eighty-four".