1289323728 has 360 divisors, whose sum is σ = 4686896448. Its totient is φ = 324086400.

The previous prime is 1289323691. The next prime is 1289323753. The reversal of 1289323728 is 8273239821.

It is a nude number because it is divisible by every one of its digits.

Its product of digits (290304) is a multiple of the sum of its prime divisors (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 41591073 + ... + 41591103.

Almost surely, 2^1289323728 is an apocalyptic number.

1289323728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1289323728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2343448224).

1289323728 is an abundant number, since it is smaller than the sum of its proper divisors (3397572720).

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

1289323728 is a wasteful number, since it uses less digits than its factorization.

1289323728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116 (or 54 counting only the distinct ones).

The product of its digits is 290304, while the sum is 45.

The square root of 1289323728 is about 35907.1542732086. The cubic root of 1289323728 is about 1088.3969725360.

The spelling of 1289323728 in words is "one billion, two hundred eighty-nine million, three hundred twenty-three thousand, seven hundred twenty-eight".