111851 has 4 divisors (see below), whose sum is σ = 114912. Its totient is φ = 108792.

The previous prime is 111847. The next prime is 111857. The reversal of 111851 is 158111.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 158111 = 43 ⋅3677.

It is a cyclic number.

It is not a de Polignac number, because 111851 - 2² = 111847 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111857) 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, 1475 + ... + 1548.

It is an arithmetic number, because the mean of its divisors is an integer number (28728).

2¹¹¹⁸⁵¹ is an apocalyptic number.

111851 is a deficient number, since it is larger than the sum of its proper divisors (3061).

111851 is an equidigital number, since it uses as much as digits as its factorization.

111851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3060.

The product of its digits is 40, while the sum is 17.

The square root of 111851 is about 334.4413251977. The cubic root of 111851 is about 48.1814601309.

Adding to 111851 its reverse (158111), we get a palindrome (269962).

The spelling of 111851 in words is "one hundred eleven thousand, eight hundred fifty-one".