111111001 has 4 divisors (see below), whose sum is σ = 111182004. Its totient is φ = 111040000.

The previous prime is 111110969. The next prime is 111111017. The reversal of 111111001 is 100111111.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 99201600 + 11909401 = 9960^2 + 3451^2 .

It is a cyclic number.

It is not a de Polignac number, because 111111001 - 2⁵ = 111110969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111111041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33100 + ... + 36301.

It is an arithmetic number, because the mean of its divisors is an integer number (27795501).

Almost surely, 2^111111001 is an apocalyptic number.

It is an amenable number.

111111001 is a deficient number, since it is larger than the sum of its proper divisors (71003).

111111001 is an equidigital number, since it uses as much as digits as its factorization.

111111001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71002.

The product of its (nonzero) digits is 1, while the sum is 7.

The square root of 111111001 is about 10540.9203108647. The cubic root of 111111001 is about 480.7496979614.

Adding to 111111001 its reverse (100111111), we get a palindrome (211222112).

It can be divided in two parts, 11111 and 1001, that multiplied together give a palindrome (11122111).

The spelling of 111111001 in words is "one hundred eleven million, one hundred eleven thousand, one".