1280800 has 36 divisors (see below), whose sum is σ = 3128706. Its totient is φ = 512000.

The previous prime is 1280791. The next prime is 1280803. The reversal of 1280800 is 80821.

It is a happy number.

1280800 is a nontrivial binomial coefficient, being equal to C(1601, 2).

It can be written as a sum of positive squares in 3 ways, for example, as 1245456 + 35344 = 1116^2 + 188^2 .

It is not an unprimeable number, because it can be changed into a prime (1280803) 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, 1 + ... + 1600.

2^1280800 is an apocalyptic number.

1280800 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1280800 is the 1600-th triangular number.

1280800 is the 534-th centered nonagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1280800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1564353).

1280800 is an abundant number, since it is smaller than the sum of its proper divisors (1847906).

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

1280800 is a wasteful number, since it uses less digits than its factorization.

1280800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1621 (or 1608 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 1280800 is about 1131.7243480636. The cubic root of 1280800 is about 108.5993200997.

It can be divided in two parts, 1280 and 800, that added together give a triangular number (2080 = T₆₄).

The spelling of 1280800 in words is "one million, two hundred eighty thousand, eight hundred".