1011111111001 has 16 divisors (see below), whose sum is σ = 1032662970000. Its totient is φ = 989770503168.

The previous prime is 1011111110899. The next prime is 1011111111007. The reversal of 1011111111001 is 1001111111101.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 210291947776 + 800819163225 = 458576^2 + 894885^2 .

It is a cyclic number.

It is not a de Polignac number, because 1011111111001 - 2¹³ = 1011111102809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1011111111007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69489675 + ... + 69504223.

It is an arithmetic number, because the mean of its divisors is an integer number (64541435625).

Almost surely, 2^{1011111111001} is an apocalyptic number.

It is an amenable number.

1011111111001 is a deficient number, since it is larger than the sum of its proper divisors (21551858999).

1011111111001 is a wasteful number, since it uses less digits than its factorization.

1011111111001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21708.

The product of its (nonzero) digits is 1, while the sum is 10.

Adding to 1011111111001 its reverse (1001111111101), we get a palindrome (2012222222102).

It can be divided in two parts, 101111111100 and 1, that added together give a palindrome (101111111101).

The spelling of 1011111111001 in words is "one trillion, eleven billion, one hundred eleven million, one hundred eleven thousand, one".