1280740809 has 16 divisors (see below), whose sum is σ = 1875686400. Its totient is φ = 773719056.

The previous prime is 1280740807. The next prime is 1280740841. The reversal of 1280740809 is 9080470821.

It is not a de Polignac number, because 1280740809 - 2¹ = 1280740807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1280740807) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 487149 + ... + 489770.

It is an arithmetic number, because the mean of its divisors is an integer number (117230400).

Almost surely, 2^1280740809 is an apocalyptic number.

1280740809 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1280740809 is a deficient number, since it is larger than the sum of its proper divisors (594945591).

1280740809 is a wasteful number, since it uses less digits than its factorization.

1280740809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 976964.

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 1280740809 is about 35787.4392629593. The cubic root of 1280740809 is about 1085.9764713453.

The spelling of 1280740809 in words is "one billion, two hundred eighty million, seven hundred forty thousand, eight hundred nine".