1001001111001 has 2 divisors, whose sum is σ = 1001001111002. Its totient is φ = 1001001111000.

The previous prime is 1001001110969. The next prime is 1001001111017. The reversal of 1001001111001 is 1001111001001.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 939447501001 + 61553610000 = 969251^2 + 248100^2 .

It is an emirp because it is prime and its reverse (1001111001001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1001001111001 - 2⁵ = 1001001110969 is a prime.

It is not a weakly prime, because it can be changed into another prime (1001002111001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500500555500 + 500500555501.

It is an arithmetic number, because the mean of its divisors is an integer number (500500555501).

Almost surely, 2^{1001001111001} is an apocalyptic number.

It is an amenable number.

1001001111001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001001111001 is an equidigital number, since it uses as much as digits as its factorization.

1001001111001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1, while the sum is 7.

Adding to 1001001111001 its reverse (1001111001001), we get a palindrome (2002112112002).

The spelling of 1001001111001 in words is "one trillion, one billion, one million, one hundred eleven thousand, one".