55518231 has 4 divisors (see below), whose sum is σ = 74024312. Its totient is φ = 37012152.

The previous prime is 55518191. The next prime is 55518257. The reversal of 55518231 is 13281555.

55518231 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 55518231 - 2⁹ = 55517719 is a prime.

It is a super-2 number, since 2×55518231² = 6164547946738722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55511231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9253036 + ... + 9253041.

It is an arithmetic number, because the mean of its divisors is an integer number (18506078).

Almost surely, 2^55518231 is an apocalyptic number.

55518231 is a deficient number, since it is larger than the sum of its proper divisors (18506081).

55518231 is a wasteful number, since it uses less digits than its factorization.

55518231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18506080.

The product of its digits is 6000, while the sum is 30.

The square root of 55518231 is about 7451.0556970137. The cubic root of 55518231 is about 381.4859431399.

Adding to 55518231 its reverse (13281555), we get a palindrome (68799786).

The spelling of 55518231 in words is "fifty-five million, five hundred eighteen thousand, two hundred thirty-one".