1291326601 has 2 divisors, whose sum is σ = 1291326602. Its totient is φ = 1291326600.

The previous prime is 1291326599. The next prime is 1291326661. The reversal of 1291326601 is 1066231921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 689115001 + 602211600 = 26251^2 + 24540^2 .

It is a cyclic number.

It is not a de Polignac number, because 1291326601 - 2¹ = 1291326599 is a prime.

Together with 1291326599, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1291326661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645663300 + 645663301.

It is an arithmetic number, because the mean of its divisors is an integer number (645663301).

Almost surely, 2^1291326601 is an apocalyptic number.

It is an amenable number.

1291326601 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291326601 is an equidigital number, since it uses as much as digits as its factorization.

1291326601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 1291326601 is about 35935.0330596759. The cubic root of 1291326601 is about 1088.9602634693.

The spelling of 1291326601 in words is "one billion, two hundred ninety-one million, three hundred twenty-six thousand, six hundred one".