1280840084605 has 4 divisors (see below), whose sum is σ = 1537008101532. Its totient is φ = 1024672067680.

The previous prime is 1280840084569. The next prime is 1280840084611. The reversal of 1280840084605 is 5064800480821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 197098705764 + 1083741378841 = 443958^2 + 1041029^2 .

It is not a de Polignac number, because 1280840084605 - 2¹³ = 1280840076413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128084008456 + ... + 128084008465.

It is an arithmetic number, because the mean of its divisors is an integer number (384252025383).

Almost surely, 2^{1280840084605} is an apocalyptic number.

It is an amenable number.

1280840084605 is a deficient number, since it is larger than the sum of its proper divisors (256168016927).

1280840084605 is an equidigital number, since it uses as much as digits as its factorization.

1280840084605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256168016926.

The product of its (nonzero) digits is 491520, while the sum is 46.

The spelling of 1280840084605 in words is "one trillion, two hundred eighty billion, eight hundred forty million, eighty-four thousand, six hundred five".