11111111011001 has 24 divisors (see below), whose sum is σ = 12356742865824. Its totient is φ = 9955433093760.

The previous prime is 11111111010997. The next prime is 11111111011037. The reversal of 11111111011001 is 10011011111111.

It is not a de Polignac number, because 11111111011001 - 2² = 11111111010997 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11111111011081) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1030271 + ... + 4825316.

It is an arithmetic number, because the mean of its divisors is an integer number (514864286076).

Almost surely, 2^{11111111011001} is an apocalyptic number.

It is an amenable number.

11111111011001 is a deficient number, since it is larger than the sum of its proper divisors (1245631854823).

11111111011001 is a wasteful number, since it uses less digits than its factorization.

11111111011001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5855861 (or 5855838 counting only the distinct ones).

The product of its (nonzero) digits is 1, while the sum is 11.

Adding to 11111111011001 its reverse (10011011111111), we get a palindrome (21122122122112).

The spelling of 11111111011001 in words is "eleven trillion, one hundred eleven billion, one hundred eleven million, eleven thousand, one".