111978 has 12 divisors (see below), whose sum is σ = 242658. Its totient is φ = 37320.

The previous prime is 111977. The next prime is 111997. The reversal of 111978 is 879111.

It can be written as a sum of positive squares in only one way, i.e., 110889 + 1089 = 333^2 + 33^2 .

It is not an unprimeable number, because it can be changed into a prime (111973) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3093 + ... + 3128.

2¹¹¹⁹⁷⁸ is an apocalyptic number.

111978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

111978 is an abundant number, since it is smaller than the sum of its proper divisors (130680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

111978 is a wasteful number, since it uses less digits than its factorization.

111978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6229 (or 6226 counting only the distinct ones).

The product of its digits is 504, while the sum is 27.

The square root of 111978 is about 334.6311402126. The cubic root of 111978 is about 48.1996889382.

It can be divided in two parts, 111 and 978, that added together give a square (1089 = 33²).

The spelling of 111978 in words is "one hundred eleven thousand, nine hundred seventy-eight".