55111813 has 4 divisors (see below), whose sum is σ = 55134880. Its totient is φ = 55088748.

The previous prime is 55111801. The next prime is 55111843. The reversal of 55111813 is 31811155.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31811155 = 5 ⋅6362231.

It is a cyclic number.

It is not a de Polignac number, because 55111813 - 2⁵ = 55111781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55111843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7473 + ... + 12886.

It is an arithmetic number, because the mean of its divisors is an integer number (13783720).

Almost surely, 2^55111813 is an apocalyptic number.

It is an amenable number.

55111813 is a deficient number, since it is larger than the sum of its proper divisors (23067).

55111813 is a wasteful number, since it uses less digits than its factorization.

55111813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23066.

The product of its digits is 600, while the sum is 25.

The square root of 55111813 is about 7423.7330905684. The cubic root of 55111813 is about 380.5527804377.

Adding to 55111813 its reverse (31811155), we get a palindrome (86922968).

The spelling of 55111813 in words is "fifty-five million, one hundred eleven thousand, eight hundred thirteen".