78111 has 16 divisors (see below), whose sum is σ = 126720. Its totient is φ = 47160.

The previous prime is 78101. The next prime is 78121. The reversal of 78111 is 11187.

It is an interprime number because it is at equal distance from previous prime (78101) and next prime (78121).

It is not a de Polignac number, because 78111 - 2⁵ = 78079 is a prime.

It is a super-2 number, since 2×78111² = 12202656642, which contains 22 as substring.

It is an Ulam number.

78111 is a modest number, since divided by 111 gives 78 as remainder.

It is a nialpdrome in base 5.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78101) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 166 + ... + 428.

It is an arithmetic number, because the mean of its divisors is an integer number (7920).

2⁷⁸¹¹¹ is an apocalyptic number.

78111 is a deficient number, since it is larger than the sum of its proper divisors (48609).

78111 is a wasteful number, since it uses less digits than its factorization.

78111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283 (or 277 counting only the distinct ones).

The product of its digits is 56, while the sum is 18.

The square root of 78111 is about 279.4834521041. The cubic root of 78111 is about 42.7468449503.

Adding to 78111 its reverse (11187), we get a palindrome (89298).

It can be divided in two parts, 7 and 8111, that added together give a palindrome (8118).

The spelling of 78111 in words is "seventy-eight thousand, one hundred eleven".