1111155555 has 64 divisors (see below), whose sum is σ = 1875363840. Its totient is φ = 561254400.

The previous prime is 1111155541. The next prime is 1111155559. The reversal of 1111155555 is 5555511111.

It is a happy number.

It is a Cunningham number, because it is equal to 33334²-1.

It is not a de Polignac number, because 1111155555 - 2⁶ = 1111155491 is a prime.

It is a nude number because it is divisible by every one of its digits.

It is a plaindrome in base 10.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (1111155559) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4100070 + ... + 4100340.

It is an arithmetic number, because the mean of its divisors is an integer number (29302560).

Almost surely, 2^1111155555 is an apocalyptic number.

1111155555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1111155555 is a deficient number, since it is larger than the sum of its proper divisors (764208285).

1111155555 is a wasteful number, since it uses less digits than its factorization.

1111155555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 492.

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

The square root of 1111155555 is about 33333.9999850003. Note that the first 4 decimals coincide. The cubic root of 1111155555 is about 1035.7579782168.

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

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

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

The spelling of 1111155555 in words is "one billion, one hundred eleven million, one hundred fifty-five thousand, five hundred fifty-five".