5555511111 has 16 divisors (see below), whose sum is σ = 7616060928. Its totient is φ = 3599985600.

The previous prime is 5555511109. The next prime is 5555511139. The reversal of 5555511111 is 1111155555.

It is a happy number.

It is not a de Polignac number, because 5555511111 - 2¹ = 5555511109 is a prime.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5555511151) 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 15 ways as a sum of consecutive naturals, for example, 50001 + ... + 116666.

It is an arithmetic number, because the mean of its divisors is an integer number (476003808).

Almost surely, 2^5555511111 is an apocalyptic number.

5555511111 is a deficient number, since it is larger than the sum of its proper divisors (2060549817).

5555511111 is a wasteful number, since it uses less digits than its factorization.

5555511111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166982.

The product of its digits is 3125, while the sum is 30.

The square root of 5555511111 is about 74535.3011062543. The cubic root of 5555511111 is about 1771.0928923530.

Adding to 5555511111 its reverse (1111155555), we get a palindrome (6666666666).

Subtracting from 5555511111 its reverse (1111155555), we obtain a square (4444355556 = 66666²).

It can be divided in two parts, 55555 and 11111, that added together give a palindrome (66666).

The spelling of 5555511111 in words is "five billion, five hundred fifty-five million, five hundred eleven thousand, one hundred eleven".