1280440536 has 32 divisors (see below), whose sum is σ = 3208766400. Its totient is φ = 425791520.

The previous prime is 1280440531. The next prime is 1280440559. The reversal of 1280440536 is 6350440821.

It is a junction number, because it is equal to n+sod(n) for n = 1280440497 and 1280440506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1280440531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53610 + ... + 73721.

It is an arithmetic number, because the mean of its divisors is an integer number (100273950).

Almost surely, 2^1280440536 is an apocalyptic number.

It is an amenable number.

1280440536 is an abundant number, since it is smaller than the sum of its proper divisors (1928325864).

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

1280440536 is a wasteful number, since it uses less digits than its factorization.

1280440536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127759 (or 127755 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 33.

The square root of 1280440536 is about 35783.2437881196. The cubic root of 1280440536 is about 1085.8915947129.

The spelling of 1280440536 in words is "one billion, two hundred eighty million, four hundred forty thousand, five hundred thirty-six".