111111011111001 has 32 divisors (see below), whose sum is σ = 168481212788736. Its totient is φ = 64522523160000.

The previous prime is 111111011110999. The next prime is 111111011111033. The reversal of 111111011111001 is 100111110111111.

It is not a de Polignac number, because 111111011111001 - 2¹ = 111111011110999 is a prime.

It is not an unprimeable number, because it can be changed into a prime (111111011151001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 537584371 + ... + 537791016.

It is an arithmetic number, because the mean of its divisors is an integer number (5265037899648).

Almost surely, 2^{111111011111001} is an apocalyptic number.

111111011111001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111111011111001 is a deficient number, since it is larger than the sum of its proper divisors (57370201677735).

111111011111001 is a wasteful number, since it uses less digits than its factorization.

111111011111001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1075375533.

The product of its (nonzero) digits is 1, while the sum is 12.

Adding to 111111011111001 its reverse (100111110111111), we get a palindrome (211222121222112).

The spelling of 111111011111001 in words is "one hundred eleven trillion, one hundred eleven billion, eleven million, one hundred eleven thousand, one".