1280643960 has 32 divisors (see below), whose sum is σ = 3841932240. Its totient is φ = 341505024.

The previous prime is 1280643941. The next prime is 1280644019. The reversal of 1280643960 is 693460821.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5335897 + ... + 5336136.

Almost surely, 2^1280643960 is an apocalyptic number.

1280643960 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1280643960 is an abundant number, since it is smaller than the sum of its proper divisors (2561288280).

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

1280643960 is a wasteful number, since it uses less digits than its factorization.

1280643960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10672047 (or 10672043 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 1280643960 is about 35786.0861229613. The cubic root of 1280643960 is about 1085.9490969836.

The spelling of 1280643960 in words is "one billion, two hundred eighty million, six hundred forty-three thousand, nine hundred sixty".