1281173405 has 4 divisors (see below), whose sum is σ = 1537408092. Its totient is φ = 1024938720.

The previous prime is 1281173357. The next prime is 1281173407. The reversal of 1281173405 is 5043711821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5043711821 = 157 ⋅32125553.

It can be written as a sum of positive squares in 2 ways, for example, as 540190564 + 740982841 = 23242^2 + 27221^2 .

It is not a de Polignac number, because 1281173405 - 2¹⁴ = 1281157021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281173407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128117336 + ... + 128117345.

It is an arithmetic number, because the mean of its divisors is an integer number (384352023).

Almost surely, 2^1281173405 is an apocalyptic number.

It is an amenable number.

1281173405 is a deficient number, since it is larger than the sum of its proper divisors (256234687).

1281173405 is an equidigital number, since it uses as much as digits as its factorization.

1281173405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256234686.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 1281173405 is about 35793.4827168299. The cubic root of 1281173405 is about 1086.0987277224.

The spelling of 1281173405 in words is "one billion, two hundred eighty-one million, one hundred seventy-three thousand, four hundred five".