1321286905 has 4 divisors (see below), whose sum is σ = 1585544292. Its totient is φ = 1057029520.

The previous prime is 1321286899. The next prime is 1321286963. The reversal of 1321286905 is 5096821231.

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 310746384 + 1010540521 = 17628^2 + 31789^2 .

It is not a de Polignac number, because 1321286905 - 2¹¹ = 1321284857 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 132128686 + ... + 132128695.

It is an arithmetic number, because the mean of its divisors is an integer number (396386073).

Almost surely, 2^1321286905 is an apocalyptic number.

It is an amenable number.

1321286905 is a deficient number, since it is larger than the sum of its proper divisors (264257387).

1321286905 is an equidigital number, since it uses as much as digits as its factorization.

1321286905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264257386.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 1321286905 is about 36349.5103818470. The cubic root of 1321286905 is about 1097.3176808097.

The spelling of 1321286905 in words is "one billion, three hundred twenty-one million, two hundred eighty-six thousand, nine hundred five".