55820111 has 4 divisors (see below), whose sum is σ = 55894224. Its totient is φ = 55746000.

The previous prime is 55820101. The next prime is 55820113. The reversal of 55820111 is 11102855.

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

It is a cyclic number.

It is not a de Polignac number, because 55820111 - 2¹⁸ = 55557967 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 (55820113) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35915 + ... + 37436.

It is an arithmetic number, because the mean of its divisors is an integer number (13973556).

Almost surely, 2^55820111 is an apocalyptic number.

55820111 is a deficient number, since it is larger than the sum of its proper divisors (74113).

55820111 is an equidigital number, since it uses as much as digits as its factorization.

55820111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74112.

The product of its (nonzero) digits is 400, while the sum is 23.

The square root of 55820111 is about 7471.2857661851. The cubic root of 55820111 is about 382.1761360734.

Adding to 55820111 its reverse (11102855), we get a palindrome (66922966).

The spelling of 55820111 in words is "fifty-five million, eight hundred twenty thousand, one hundred eleven".