111111111001001 has 32 divisors (see below), whose sum is σ = 117652113532800. Its totient is φ = 104641130880000.

The previous prime is 111111111000991. The next prime is 111111111001021. The reversal of 111111111001001 is 100100111111111.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111111111001001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111111111001021) 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, 6320664230 + ... + 6320681808.

It is an arithmetic number, because the mean of its divisors is an integer number (3676628547900).

Almost surely, 2^{111111111001001} is an apocalyptic number.

It is an amenable number.

111111111001001 is a deficient number, since it is larger than the sum of its proper divisors (6541002531799).

111111111001001 is a wasteful number, since it uses less digits than its factorization.

111111111001001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20201.

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

Adding to 111111111001001 its reverse (100100111111111), we get a palindrome (211211222112112).

It can be divided in two parts, 11111111 and 1001001, that multiplied together give a palindrome (11122233222111).

The spelling of 111111111001001 in words is "one hundred eleven trillion, one hundred eleven billion, one hundred eleven million, one thousand, one".