1280378536 has 128 divisors (see below), whose sum is σ = 2781216000. Its totient is φ = 549255168.

The previous prime is 1280378531. The next prime is 1280378543. The reversal of 1280378536 is 6358730821.

It is a junction number, because it is equal to n+sod(n) for n = 1280378492 and 1280378501.

It is not an unprimeable number, because it can be changed into a prime (1280378531) 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 31 ways as a sum of consecutive naturals, for example, 7400946 + ... + 7401118.

It is an arithmetic number, because the mean of its divisors is an integer number (21728250).

Almost surely, 2^1280378536 is an apocalyptic number.

It is an amenable number.

1280378536 is an abundant number, since it is smaller than the sum of its proper divisors (1500837464).

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

1280378536 is a wasteful number, since it uses less digits than its factorization.

1280378536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323 (or 319 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 43.

The square root of 1280378536 is about 35782.3774503596. The cubic root of 1280378536 is about 1085.8740678375.

The spelling of 1280378536 in words is "one billion, two hundred eighty million, three hundred seventy-eight thousand, five hundred thirty-six".