55555555 has 32 divisors (see below), whose sum is σ = 74996928. Its totient is φ = 39168000.

The previous prime is 55555553. The next prime is 55555559.

55555555 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 55555555 - 2¹ = 55555553 is a prime.

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

It is a Duffinian number.

55555555 is a modest number, since divided by 55555 gives 555 as remainder.

55555555 is a nontrivial repdigit in base 10.

It is a plaindrome in base 10.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (55555553) by changing a digit.

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

It is an upside-down number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 405447 + ... + 405583.

It is an arithmetic number, because the mean of its divisors is an integer number (2343654).

Almost surely, 2^55555555 is an apocalyptic number.

55555555 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

55555555 is a deficient number, since it is larger than the sum of its proper divisors (19441373).

55555555 is a wasteful number, since it uses less digits than its factorization.

55555555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327.

The product of its digits is 390625, while the sum is 40.

The square root of 55555555 is about 7453.5598877315. The cubic root of 55555555 is about 381.5714129125.

The spelling of 55555555 in words is "fifty-five million, five hundred fifty-five thousand, five hundred fifty-five".