1311001001 has 4 divisors (see below), whose sum is σ = 1311274692. Its totient is φ = 1310727312.

The previous prime is 1311000991. The next prime is 1311001009. The reversal of 1311001001 is 1001001131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1001001131 = 13 ⋅77000087.

It can be written as a sum of positive squares in 2 ways, for example, as 387144976 + 923856025 = 19676^2 + 30395^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311001001 - 2¹⁴ = 1310984617 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1311001001.

It is not an unprimeable number, because it can be changed into a prime (1311001009) 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 in 3 ways as a sum of consecutive naturals, for example, 129530 + ... + 139283.

It is an arithmetic number, because the mean of its divisors is an integer number (327818673).

Almost surely, 2^1311001001 is an apocalyptic number.

It is an amenable number.

1311001001 is a deficient number, since it is larger than the sum of its proper divisors (273691).

1311001001 is an equidigital number, since it uses as much as digits as its factorization.

1311001001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273690.

The product of its (nonzero) digits is 3, while the sum is 8.

The square root of 1311001001 is about 36207.7478034743. The cubic root of 1311001001 is about 1094.4628074709.

Adding to 1311001001 its reverse (1001001131), we get a palindrome (2312002132).

It can be divided in two parts, 131 and 1001001, that multiplied together give a palindrome (131131131).

The spelling of 1311001001 in words is "one billion, three hundred eleven million, one thousand, one".