1288091389 has 8 divisors (see below), whose sum is σ = 1389621240. Its totient is φ = 1186910976.

The previous prime is 1288091327. The next prime is 1288091401. The reversal of 1288091389 is 9831908821.

It can be written as a sum of positive squares in 4 ways, for example, as 2295225 + 1285796164 = 1515^2 + 35858^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1288091389 - 2⁹ = 1288090877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1288097389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79672 + ... + 94465.

It is an arithmetic number, because the mean of its divisors is an integer number (173702655).

Almost surely, 2^1288091389 is an apocalyptic number.

It is an amenable number.

1288091389 is a deficient number, since it is larger than the sum of its proper divisors (101529851).

1288091389 is a wasteful number, since it uses less digits than its factorization.

1288091389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174719.

The product of its (nonzero) digits is 248832, while the sum is 49.

The square root of 1288091389 is about 35889.9900947325. The cubic root of 1288091389 is about 1088.0500977711.

The spelling of 1288091389 in words is "one billion, two hundred eighty-eight million, ninety-one thousand, three hundred eighty-nine".