121878 has 32 divisors (see below), whose sum is σ = 282720. Its totient is φ = 38880.

The previous prime is 121867. The next prime is 121883. The reversal of 121878 is 878121.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

121878 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1968 + ... + 2028.

It is an arithmetic number, because the mean of its divisors is an integer number (8835).

2¹²¹⁸⁷⁸ is an apocalyptic number.

121878 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 121878, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141360).

121878 is an abundant number, since it is smaller than the sum of its proper divisors (160842).

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

121878 is a wasteful number, since it uses less digits than its factorization.

121878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109 (or 103 counting only the distinct ones).

The product of its digits is 896, while the sum is 27.

The square root of 121878 is about 349.1102977570. The cubic root of 121878 is about 49.5802188724.

Adding to 121878 its reverse (878121), we get a palindrome (999999).

It can be divided in two parts, 1218 and 78, that added together give a 4-th power (1296 = 6⁴).

The spelling of 121878 in words is "one hundred twenty-one thousand, eight hundred seventy-eight".