1291946321 has 4 divisors (see below), whose sum is σ = 1292350644. Its totient is φ = 1291542000.

The previous prime is 1291946311. The next prime is 1291946333. The reversal of 1291946321 is 1236491921.

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 483340225 + 808606096 = 21985^2 + 28436^2 .

It is a cyclic number.

It is not a de Polignac number, because 1291946321 - 2¹⁰ = 1291945297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1291946311) 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 3 ways as a sum of consecutive naturals, for example, 197330 + ... + 203771.

It is an arithmetic number, because the mean of its divisors is an integer number (323087661).

Almost surely, 2^1291946321 is an apocalyptic number.

It is an amenable number.

1291946321 is a deficient number, since it is larger than the sum of its proper divisors (404323).

1291946321 is an equidigital number, since it uses as much as digits as its factorization.

1291946321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404322.

The product of its digits is 23328, while the sum is 38.

The square root of 1291946321 is about 35943.6548086029. The cubic root of 1291946321 is about 1089.1344364289.

The spelling of 1291946321 in words is "one billion, two hundred ninety-one million, nine hundred forty-six thousand, three hundred twenty-one".