1280645760 has 128 divisors (see below), whose sum is σ = 4097021760. Its totient is φ = 340254720.

The previous prime is 1280645759. The next prime is 1280645767. The reversal of 1280645760 is 675460821.

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (1280645767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 599895 + ... + 602025.

Almost surely, 2^1280645760 is an apocalyptic number.

1280645760 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 1280645760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2048510880).

1280645760 is an abundant number, since it is smaller than the sum of its proper divisors (2816376000).

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

1280645760 is a wasteful number, since it uses less digits than its factorization.

1280645760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2466 (or 2454 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 1280645760 is about 35786.1112723917. Note that the first 3 decimals coincide. The cubic root of 1280645760 is about 1085.9496057661.

The spelling of 1280645760 in words is "one billion, two hundred eighty million, six hundred forty-five thousand, seven hundred sixty".