11111001011001 has 32 divisors (see below), whose sum is σ = 16520055027840. Its totient is φ = 7380652852800.

The previous prime is 11111001010987. The next prime is 11111001011009. The reversal of 11111001011001 is 10011010011111.

It is not a de Polignac number, because 11111001011001 - 2¹⁹ = 11111000486713 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (11111001011009) 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 31 ways as a sum of consecutive naturals, for example, 42438586 + ... + 42699596.

It is an arithmetic number, because the mean of its divisors is an integer number (516251719620).

Almost surely, 2^{11111001011001} is an apocalyptic number.

It is an amenable number.

11111001011001 is a deficient number, since it is larger than the sum of its proper divisors (5409054016839).

11111001011001 is a wasteful number, since it uses less digits than its factorization.

11111001011001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266694 (or 266688 counting only the distinct ones).

The product of its (nonzero) digits is 1, while the sum is 9.

Adding to 11111001011001 its reverse (10011010011111), we get a palindrome (21122011022112).

The spelling of 11111001011001 in words is "eleven trillion, one hundred eleven billion, one million, eleven thousand, one".