1289728800 has 432 divisors, whose sum is σ = 4952073672. Its totient is φ = 314572800.

The previous prime is 1289728793. The next prime is 1289728801. The reversal of 1289728800 is 88279821.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 240746256 + 1048982544 = 15516^2 + 32388^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1289728801) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 5018272 + ... + 5018528.

Almost surely, 2^1289728800 is an apocalyptic number.

1289728800 is a gapful number since it is divisible by the number (10) 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 1289728800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2476036836).

1289728800 is an abundant number, since it is smaller than the sum of its proper divisors (3662344872).

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

1289728800 is a wasteful number, since it uses less digits than its factorization.

1289728800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 341 (or 325 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

The square root of 1289728800 is about 35912.7943774917. The cubic root of 1289728800 is about 1088.5109426135.

The spelling of 1289728800 in words is "one billion, two hundred eighty-nine million, seven hundred twenty-eight thousand, eight hundred".